485BPOS

As filed with the U.S. Securities and Exchange Commission on June 4, 2013

Securities Act File No. 33-43446

Investment Company Act File No. 811-06444

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT

UNDER
THE SECURITIES ACT OF 1933	x
Pre-Effective Amendment No.
Post-Effective Amendment No. 276	x

and/or

REGISTRATION STATEMENT

UNDER

THE INVESTMENT COMPANY ACT OF 1940	x
Amendment No. 276

(Check appropriate box or boxes)

Legg Mason Partners Equity Trust

(Exact Name of Registrant as Specified in Charter)

620 Eighth Avenue, 49th Floor, New York, New York	10018
(Address of Principal Executive Offices)	(Zip Code)

Registrant’s Telephone Number, including Area Code (877) 721-1926

Robert I. Frenkel

Legg Mason Partners Equity Trust

100 First Stamford Place

Stamford, Connecticut 06902

(Name and Address of Agent for Service)

COPY TO:

Benjamin J. Haskin, Esq.

Willkie Farr & Gallagher LLP

1875 K Street, N.W.

Washington, D.C. 20006

Continuous

(Approximate Date of Proposed Offering)

It is proposed that this filing will become effective:

x immediately upon filing pursuant to paragraph (b)

¨ on              pursuant to paragraph (b)

¨ 60 days after filing pursuant to paragraph (a)(1)

¨ on              pursuant to paragraph (a)(1)

¨ 75 days after filing pursuant to paragraph (a)(2)

¨ on              pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

¨ This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

This filing relates solely to Legg Mason Target Retirement 2015, Legg Mason Target Retirement 2020, Legg Mason Target Retirement 2025, Legg Mason Target Retirement 2030, Legg Mason Target Retirement 2035, Legg Mason Target Retirement 2040, Legg Mason Target Retirement 2045, Legg Mason Target Retirement 2050 and Legg Mason Target Retirement Fund.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended (the “Securities Act”), and the Investment Company Act of 1940, as amended, the Registrant, LEGG MASON PARTNERS EQUITY TRUST, hereby certifies that it meets all the requirements for effectiveness of this Registration Statement under Rule 485(b) under the Securities Act and has duly caused this Post-Effective Amendment to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Baltimore, State of Maryland on this 4^th day of June 2013.

LEGG MASON PARTNERS EQUITY TRUST, on behalf of Legg Mason Target Retirement 2015, Legg Mason Target Retirement 2020, Legg Mason Target Retirement 2025, Legg Mason Target Retirement 2030, Legg Mason Target Retirement 2035, Legg Mason Target Retirement 2040, Legg Mason Target Retirement 2045, Legg Mason Target Retirement 2050 and Legg Mason Target Retirement Fund.

By:	/s/ Kenneth D. Fuller
	Kenneth D. Fuller
	President and Chief Executive Officer

WITNESS our hands on the date set forth below.

Pursuant to the requirements of the Securities Act, this Post-Effective Amendment to the Registration Statement has been signed below by the following persons in the capacities indicated below on June 4, 2013.

Signature	Title
/s/ Kenneth D. Fuller	President, Chief Executive Officer and Trustee
Kenneth D. Fuller
/s/ Richard F. Sennett	Principal Financial Officer
Richard F. Sennett
Paul R. Ades*	Trustee
Paul R. Ades
Andrew L. Breech*	Trustee
Andrew L. Breech
Dwight B. Crane*	Trustee
Dwight B. Crane
Frank G. Hubbard*	Trustee
Frank G. Hubbard
Howard J. Johnson*	Trustee
Howard J. Johnson
Jerome H. Miller*	Trustee
Jerome H. Miller
Ken Miller*	Trustee
Ken Miller

John J. Murphy*	Trustee
John J. Murphy
Thomas F. Schlafly*	Trustee
Thomas F. Schlafly
Jerry A. Viscione*	Trustee
Jerry A. Viscione

*By:	/s/ Kenneth D. Fuller
	Kenneth D. Fuller, as Agent

EXHIBIT INDEX

Index No.	Description of Exhibit
EX-101.INS	XBRL Instance Document
EX-101.SCH	XBRL Taxonomy Extension Schema Document
EX-101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

LEGG MASON PARTNERS EQUITY TRUST

Prospectus Date

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Jun. 01, 2013

Legg Mason Target Retirement 2020

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

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Legg Mason Target Retirement 2020

Objective [Heading]

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Investment objectives

Objective, Primary [Text Block]

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The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Objective, Secondary [Text Block]

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From the five years before until the five years after the fund’s target retirement date of 2020 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Expense [Heading]

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Fees and expenses of the fund

Expense Narrative [Text Block]

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The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder Fees Caption [Text]

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Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

December 31, 2014

Portfolio Turnover [Heading]

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Portfolio turnover.

Portfolio Turnover [Text Block]

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The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 48% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

48.00%

Expense Breakpoint Discounts [Text]

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You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

25,000

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

“Other expenses” are estimated for the current fiscal year. Actual expenses may differ from estimates.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund’s shareholder reports, because the ratios in the financial highlights tables reflect the fund’s operating expenses and do not include acquired fund fees and expenses.

Expense Example [Heading]

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Example

Expense Example Narrative [Text Block]

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This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Number of years you own your shares ($)

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

Number of years you own your shares ($)

Strategy [Heading]

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Principal investment strategies

Strategy Narrative [Text Block]

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The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2020. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2020, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement 2020	58	%	37	%	5	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.
Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2035, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2035. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Risk [Heading]

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Certain risks

Risk Narrative [Text Block]

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Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 24% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 23% Russell 1000 Index, 22% Barclays U.S. Aggregate Index (an index of fixed income securities), 15% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index, 5% MSCI Emerging Markets Index and 1% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-877-721-1926

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class)

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Total returns (before taxes) (%)

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Calendar Years ended December 31

Best quarter
(06/30/2009): 18.30

Worst quarter
(09/30/2011): (11.99)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/2013, was 3.82

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns (for periods ended December 31, 2012) (%)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Legg Mason Target Retirement 2020 | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.46%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.40%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.25%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

685

3 years

rr_ExpenseExampleYear03

1,552

5 years

rr_ExpenseExampleYear05

2,429

10 years

rr_ExpenseExampleYear10

4,667

1 year

rr_ExpenseExampleNoRedemptionYear01

685

3 years

rr_ExpenseExampleNoRedemptionYear03

1,552

5 years

rr_ExpenseExampleNoRedemptionYear05

2,429

10 years

rr_ExpenseExampleNoRedemptionYear10

4,667

1 year

rr_AverageAnnualReturnYear01

7.40%

Since inception

rr_AverageAnnualReturnSinceInception

3.36%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2020 | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

1.00%

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.36%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.05%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.15%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

293

3 years

rr_ExpenseExampleYear03

1,234

5 years

rr_ExpenseExampleYear05

2,274

10 years

rr_ExpenseExampleYear10

4,868

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,234

5 years

rr_ExpenseExampleNoRedemptionYear05

2,274

10 years

rr_ExpenseExampleNoRedemptionYear10

4,868

2009

rr_AnnualReturn2009

26.57%

2010

rr_AnnualReturn2010

12.89%

2011

rr_AnnualReturn2011

(2.26%)

2012

rr_AnnualReturn2012

13.04%

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date return as of the most recent calendar quarter

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

3.82%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

18.30%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

11.99%

1 year

rr_AverageAnnualReturnYear01

12.04%

Since inception

rr_AverageAnnualReturnSinceInception

4.02%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2020 | Class FI

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

2.73%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.67%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.52%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

117

3 years

rr_ExpenseExampleYear03

890

5 years

rr_ExpenseExampleYear05

1,683

10 years

rr_ExpenseExampleYear10

3,759

1 year

rr_ExpenseExampleNoRedemptionYear01

117

3 years

rr_ExpenseExampleNoRedemptionYear03

890

5 years

rr_ExpenseExampleNoRedemptionYear05

1,683

10 years

rr_ExpenseExampleNoRedemptionYear10

3,759

1 year

rr_AverageAnnualReturnYear01

13.99%

Since inception

rr_AverageAnnualReturnSinceInception

4.80%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2020 | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

3.35%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.54%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.14%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.40%

1 year

rr_ExpenseExampleYear01

143

3 years

rr_ExpenseExampleYear03

1,088

5 years

rr_ExpenseExampleYear05

2,042

10 years

rr_ExpenseExampleYear10

4,465

1 year

rr_ExpenseExampleNoRedemptionYear01

143

3 years

rr_ExpenseExampleNoRedemptionYear03

1,088

5 years

rr_ExpenseExampleNoRedemptionYear05

2,042

10 years

rr_ExpenseExampleNoRedemptionYear10

4,465

1 year

rr_AverageAnnualReturnYear01

13.62%

Since inception

rr_AverageAnnualReturnSinceInception

4.52%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2020 | Class R1

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.35%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.04%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.14%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

193

3 years

rr_ExpenseExampleYear03

1,232

5 years

rr_ExpenseExampleYear05

2,270

10 years

rr_ExpenseExampleYear10

4,861

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,232

5 years

rr_ExpenseExampleNoRedemptionYear05

2,270

10 years

rr_ExpenseExampleNoRedemptionYear10

4,861

Legg Mason Target Retirement 2020 | Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.16%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.85%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.00%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.85%

1 year

rr_ExpenseExampleYear01

87

3 years

rr_ExpenseExampleYear03

898

5 years

rr_ExpenseExampleYear05

1,728

10 years

rr_ExpenseExampleYear10

3,888

1 year

rr_ExpenseExampleNoRedemptionYear01

87

3 years

rr_ExpenseExampleNoRedemptionYear03

898

5 years

rr_ExpenseExampleNoRedemptionYear05

1,728

10 years

rr_ExpenseExampleNoRedemptionYear10

3,888

1 year

rr_AverageAnnualReturnYear01

14.24%

Since inception

rr_AverageAnnualReturnSinceInception

5.09%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2020 | Class IS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.02%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.71%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.96%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.75%

1 year

rr_ExpenseExampleYear01

77

3 years

rr_ExpenseExampleYear03

860

5 years

rr_ExpenseExampleYear05

1,664

10 years

rr_ExpenseExampleYear10

3,766

1 year

rr_ExpenseExampleNoRedemptionYear01

77

3 years

rr_ExpenseExampleNoRedemptionYear03

860

5 years

rr_ExpenseExampleNoRedemptionYear05

1,664

10 years

rr_ExpenseExampleNoRedemptionYear10

3,766

Legg Mason Target Retirement 2020 | Return after taxes on distributions | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

11.59%

Since inception

rr_AverageAnnualReturnSinceInception

3.39%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2020 | Return after taxes on distributions and sale of fund shares | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

7.82%

Since inception

rr_AverageAnnualReturnSinceInception

3.05%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2020 | Dow Jones Target 2020 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

9.23%

Since inception

rr_AverageAnnualReturnSinceInception

5.24%

Legg Mason Target Retirement 2020 | Target Retirement 2020 Composite Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

12.81%

Since inception

rr_AverageAnnualReturnSinceInception

4.76%

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[3] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[4] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[5] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

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Legg Mason Target Retirement 2020

Legg Mason Target Retirement 2020

Investment objectives

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

From the five years before until the five years after the fund’s target retirement date of 2020 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Fees and expenses of the fund

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees Legg Mason Target Retirement 2020 (USD $)		Class A		Class C	Class FI	Class R	Class R1	Class I	Class IS
Maximum sales charge (load) imposed on purchases (as a % of offering price)		5.75%		none	none	none	none	none	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)		none	[1]	1.00%	none	none	none	none	none
Small account fee ($)	[2]	15		15	none	none	none	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Annual Fund Operating Expenses Legg Mason Target Retirement 2020		Class A	Class C	Class FI	Class R	Class R1	Class I	Class IS
Management fees		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and service (12b-1) fees		0.25%	1.00%	0.25%	0.50%	1.00%	none	none
Other expenses	[1]	3.46%	3.36%	2.73%	3.35%	3.35%	3.16%	3.02%
Acquired fund fees and expenses (fees and expenses of underlying funds)		0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%
Total annual fund operating expenses	[2]	4.40%	5.05%	3.67%	4.54%	5.04%	3.85%	3.71%
Fees waived and/or expenses reimbursed	[3]	(3.25%)	(3.15%)	(2.52%)	(3.14%)	(3.14%)	(3.00%)	(2.96%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses		1.15%	1.90%	1.15%	1.40%	1.90%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Number of years you own your shares ($)

Expense Example Legg Mason Target Retirement 2020 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,552	2,429	4,667
Class C	293	1,234	2,274	4,868
Class FI	117	890	1,683	3,759
Class R	143	1,088	2,042	4,465
Class R1	193	1,232	2,270	4,861
Class I	87	898	1,728	3,888
Class IS	77	860	1,664	3,766

Number of years you own your shares ($)

Expense Example, No Redemption Legg Mason Target Retirement 2020 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,552	2,429	4,667
Class C	193	1,234	2,274	4,868
Class FI	117	890	1,683	3,759
Class R	143	1,088	2,042	4,465
Class R1	193	1,232	2,270	4,861
Class I	87	898	1,728	3,888
Class IS	77	860	1,664	3,766

Portfolio turnover.

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 48% of the average value of its portfolio.

Principal investment strategies

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2020. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2020, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement 2020	58	%	37	%	5	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.
Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2035, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2035. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Certain risks

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 24% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 23% Russell 1000 Index, 22% Barclays U.S. Aggregate Index (an index of fixed income securities), 15% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index, 5% MSCI Emerging Markets Index and 1% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Total returns (before taxes) (%)

Calendar Years ended December 31

Best quarter
(06/30/2009): 18.30

Worst quarter
(09/30/2011): (11.99)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/2013, was 3.82

Average annual total returns (for periods ended December 31, 2012) (%)

Average Annual Total Returns Legg Mason Target Retirement 2020	1 year	Since inception	Inception date
Class C	12.04%	4.02%	Aug. 29, 2008
Class C Return after taxes on distributions	11.59%	3.39%	Aug. 29, 2008
Class C Return after taxes on distributions and sale of fund shares	7.82%	3.05%	Aug. 29, 2008
Class A	7.40%	3.36%	Aug. 29, 2008
Class FI	13.99%	4.80%	Aug. 29, 2008
Class R	13.62%	4.52%	Aug. 29, 2008
Class I	14.24%	5.09%	Aug. 29, 2008
Dow Jones Target 2020 Index (reflects no deduction for fees, expenses or taxes)	9.23%	5.24%
Target Retirement 2020 Composite Index (reflects no deduction for fees, expenses or taxes)	12.81%	4.76%

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[1] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[2] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[3] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

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Legg Mason Target Retirement 2025

Legg Mason Target Retirement 2025

Investment objectives

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

From the five years before until the five years after the fund’s target retirement date of 2025 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Fees and expenses of the fund

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees Legg Mason Target Retirement 2025 (USD $)		Class A		Class C	Class FI	Class R	Class R1	Class I	Class IS
Maximum sales charge (load) imposed on purchases (as a % of offering price)		5.75%		none	none	none	none	none	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)		none	[1]	1.00%	none	none	none	none	none
Small account fee ($)	[2]	15		15	none	none	none	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Annual Fund Operating Expenses Legg Mason Target Retirement 2025		Class A	Class C	Class FI	Class R	Class R1	Class I	Class IS
Management fees		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and service (12b-1) fees		0.25%	1.00%	0.25%	0.50%	1.00%	none	none
Other expenses	[1]	2.74%	2.63%	2.15%	2.62%	2.62%	2.53%	2.41%
Acquired fund fees and expenses (fees and expenses of underlying funds)		0.60%	0.60%	0.60%	0.60%	0.60%	0.60%	0.60%
Total annual fund operating expenses	[2]	3.69%	4.33%	3.10%	3.82%	4.32%	3.23%	3.11%
Fees waived and/or expenses reimbursed	[3]	(2.54%)	(2.43%)	(1.95%)	(2.42%)	(2.42%)	(2.38%)	(2.36%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses		1.15%	1.90%	1.15%	1.40%	1.90%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Number of years you own your shares ($)

Expense Example Legg Mason Target Retirement 2025 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,417	2,168	4,133
Class C	293	1,092	2,003	4,333
Class FI	117	773	1,454	3,274
Class R	143	944	1,764	3,899
Class R1	193	1,090	1,999	4,326
Class I	87	771	1,481	3,367
Class IS	77	737	1,423	3,254

Number of years you own your shares ($)

Expense Example, No Redemption Legg Mason Target Retirement 2025 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,417	2,168	4,133
Class C	193	1,092	2,003	4,333
Class FI	117	773	1,454	3,274
Class R	143	944	1,764	3,899
Class R1	193	1,090	1,999	4,326
Class I	87	771	1,481	3,367
Class IS	77	737	1,423	3,254

Portfolio turnover.

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 30% of the average value of its portfolio.

Principal investment strategies

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2025. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2025, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement 2025	64	%	31	%	5	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2040, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2040. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Certain risks

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 28% Russell 1000 Index, 26% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 16% Barclays U.S. Aggregate Index (an index of fixed income securities), 15% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index, 4% MSCI Emerging Markets Index, 1% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets) and 1% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Total returns (before taxes) (%)

Calendar Years ended December 31

Best quarter
(06/30/2009): 18.49

Worst quarter
(09/30/2011): (12.96)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 4.43

Average annual total returns (for periods ended December 31, 2012) (%)

Average Annual Total Returns Legg Mason Target Retirement 2025	1 year	Since inception	Inception date
Class C	12.81%	3.67%	Aug. 29, 2008
Class C Return after taxes on distributions	12.37%	3.09%	Aug. 29, 2008
Class C Return after taxes on distributions and sale of fund shares	8.34%	2.78%	Aug. 29, 2008
Class A	8.02%	3.01%	Aug. 29, 2008
Class FI	14.77%	4.45%	Aug. 29, 2008
Class R	14.38%	4.19%	Aug. 29, 2008
Class I	14.94%	4.74%	Aug. 29, 2008
Dow Jones Target 2025 Index (reflects no deduction for fees, expenses or taxes)	10.94%	5.18%
Target Retirement 2025 Composite Index (reflects no deduction for fees, expenses or taxes)	13.65%	4.65%

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[1] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[2] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[3] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

LEGG MASON PARTNERS EQUITY TRUST

Prospectus Date

rr_ProspectusDate

Jun. 01, 2013

Legg Mason Target Retirement 2045

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Legg Mason Target Retirement 2045

Objective [Heading]

rr_ObjectiveHeading

Investment objectives

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

From the five years before until the five years after the fund’s target retirement date of 2045 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses of the fund

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

December 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover.

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

39.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

25,000

Other Expenses, New Fund, Based on Estimates [Text]

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“Other expenses” are estimated for the current fiscal year. Actual expenses may differ from estimates.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

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Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund’s shareholder reports, because the ratios in the financial highlights tables reflect the fund’s operating expenses and do not include acquired fund fees and expenses.

Expense Example [Heading]

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Example

Expense Example Narrative [Text Block]

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This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

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Number of years you own your shares ($)

Expense Example, No Redemption, By Year, Caption [Text]

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Number of years you own your shares ($)

Strategy [Heading]

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Principal investment strategies

Strategy Narrative [Text Block]

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The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2045. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2045, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement 2045	94	%	6	%	0	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2060, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2060. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Risk [Heading]

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Certain risks

Risk Narrative [Text Block]

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Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Risk Lose Money [Text]

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You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.

Bar Chart and Performance Table [Heading]

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Performance

Performance Narrative [Text Block]

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The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 51% Russell 1000 Index, 26% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 8% Russell 2000 Index, 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 4% MSCI Emerging Markets Index, 3% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets) and 3% Barclays U.S. Aggregate Index (an index of fixed income securities). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark.

Performance Availability Phone [Text]

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1-877-721-1926

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class)

Performance Past Does Not Indicate Future [Text]

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The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Bar Chart [Heading]

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Total returns (before taxes) (%)

Bar Chart Does Not Reflect Sales Loads [Text]

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Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Bar Chart Closing [Text Block]

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Calendar Years ended December 31

Best quarter
(06/30/2009): 19.62

Worst quarter
(09/30/2011): (16.65)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 6.89

Performance Table Heading

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Average annual total returns (for periods ended December 31, 2012) (%)

Performance Table Uses Highest Federal Rate

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The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

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Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

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The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Performance Table Narrative

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The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Legg Mason Target Retirement 2045 | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

5.87%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.81%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(5.66%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

685

3 years

rr_ExpenseExampleYear03

1,995

5 years

rr_ExpenseExampleYear05

3,257

10 years

rr_ExpenseExampleYear10

6,218

1 year

rr_ExpenseExampleNoRedemptionYear01

685

3 years

rr_ExpenseExampleNoRedemptionYear03

1,995

5 years

rr_ExpenseExampleNoRedemptionYear05

3,257

10 years

rr_ExpenseExampleNoRedemptionYear10

6,218

1 year

rr_AverageAnnualReturnYear01

9.22%

Since inception

rr_AverageAnnualReturnSinceInception

1.61%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2045 | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

1.00%

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

5.84%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

7.53%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(5.63%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

293

3 years

rr_ExpenseExampleYear03

1,707

5 years

rr_ExpenseExampleYear05

3,145

10 years

rr_ExpenseExampleYear10

6,433

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,707

5 years

rr_ExpenseExampleNoRedemptionYear05

3,145

10 years

rr_ExpenseExampleNoRedemptionYear10

6,433

2009

rr_AnnualReturn2009

28.43%

2010

rr_AnnualReturn2010

13.73%

2011

rr_AnnualReturn2011

(4.63%)

2012

rr_AnnualReturn2012

14.97%

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date return as of the most recent calendar quarter

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.89%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

19.62%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

16.65%

1 year

rr_AverageAnnualReturnYear01

13.97%

Since inception

rr_AverageAnnualReturnSinceInception

2.25%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2045 | Class FI

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

5.01%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.95%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(4.80%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

117

3 years

rr_ExpenseExampleYear03

1,341

5 years

rr_ExpenseExampleYear05

2,542

10 years

rr_ExpenseExampleYear10

5,446

1 year

rr_ExpenseExampleNoRedemptionYear01

117

3 years

rr_ExpenseExampleNoRedemptionYear03

1,341

5 years

rr_ExpenseExampleNoRedemptionYear05

2,542

10 years

rr_ExpenseExampleNoRedemptionYear10

5,446

1 year

rr_AverageAnnualReturnYear01

15.95%

Since inception

rr_AverageAnnualReturnSinceInception

3.01%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2045 | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

4.86%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.05%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(4.65%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.40%

1 year

rr_ExpenseExampleYear01

143

3 years

rr_ExpenseExampleYear03

1,383

5 years

rr_ExpenseExampleYear05

2,597

10 years

rr_ExpenseExampleYear10

5,523

1 year

rr_ExpenseExampleNoRedemptionYear01

143

3 years

rr_ExpenseExampleNoRedemptionYear03

1,383

5 years

rr_ExpenseExampleNoRedemptionYear05

2,597

10 years

rr_ExpenseExampleNoRedemptionYear10

5,523

1 year

rr_AverageAnnualReturnYear01

15.56%

Since inception

rr_AverageAnnualReturnSinceInception

2.74%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2045 | Class R1

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

4.86%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.55%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(4.65%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

193

3 years

rr_ExpenseExampleYear03

1,523

5 years

rr_ExpenseExampleYear05

2,811

10 years

rr_ExpenseExampleYear10

5,862

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,523

5 years

rr_ExpenseExampleNoRedemptionYear05

2,811

10 years

rr_ExpenseExampleNoRedemptionYear10

5,862

Legg Mason Target Retirement 2045 | Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

5.49%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.18%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(5.33%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.85%

1 year

rr_ExpenseExampleYear01

87

3 years

rr_ExpenseExampleYear03

1,359

5 years

rr_ExpenseExampleYear05

2,601

10 years

rr_ExpenseExampleYear10

5,581

1 year

rr_ExpenseExampleNoRedemptionYear01

87

3 years

rr_ExpenseExampleNoRedemptionYear03

1,359

5 years

rr_ExpenseExampleNoRedemptionYear05

2,601

10 years

rr_ExpenseExampleNoRedemptionYear10

5,581

1 year

rr_AverageAnnualReturnYear01

16.22%

Since inception

rr_AverageAnnualReturnSinceInception

3.29%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2045 | Class IS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

5.38%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.07%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(5.32%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.75%

1 year

rr_ExpenseExampleYear01

77

3 years

rr_ExpenseExampleYear03

1,329

5 years

rr_ExpenseExampleYear05

2,554

10 years

rr_ExpenseExampleYear10

5,505

1 year

rr_ExpenseExampleNoRedemptionYear01

77

3 years

rr_ExpenseExampleNoRedemptionYear03

1,329

5 years

rr_ExpenseExampleNoRedemptionYear05

2,554

10 years

rr_ExpenseExampleNoRedemptionYear10

5,505

Legg Mason Target Retirement 2045 | Return after taxes on distributions | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

13.67%

Since inception

rr_AverageAnnualReturnSinceInception

1.91%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2045 | Return after taxes on distributions and sale of fund shares | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

9.08%

Since inception

rr_AverageAnnualReturnSinceInception

1.71%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2045 | Dow Jones Target 2045 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

15.32%

Since inception

rr_AverageAnnualReturnSinceInception

5.01%

Legg Mason Target Retirement 2045 | Target Retirement 2045 Composite Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

16.91%

Since inception

rr_AverageAnnualReturnSinceInception

4.51%

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[3] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[4] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[5] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

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Legg Mason Target Retirement 2030

Legg Mason Target Retirement 2030

Investment objectives

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

From the five years before until the five years after the fund’s target retirement date of 2030 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Fees and expenses of the fund

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees Legg Mason Target Retirement 2030 (USD $)		Class A		Class C	Class FI	Class R	Class R1	Class I	Class IS
Maximum sales charge (load) imposed on purchases (as a % of offering price)		5.75%		none	none	none	none	none	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)		none	[1]	1.00%	none	none	none	none	none
Small account fee ($)	[2]	15		15	none	none	none	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Annual Fund Operating Expenses Legg Mason Target Retirement 2030		Class A	Class C	Class FI	Class R	Class R1	Class I	Class IS
Management fees		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and service (12b-1) fees		0.25%	1.00%	0.25%	0.50%	1.00%	none	none
Other expenses	[1]	3.88%	3.50%	3.00%	3.26%	3.26%	3.32%	3.19%
Acquired fund fees and expenses (fees and expenses of underlying funds)		0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%
Total annual fund operating expenses	[2]	4.82%	5.19%	3.94%	4.45%	4.95%	4.01%	3.88%
Fees waived and/or expenses reimbursed	[3]	(3.67%)	(3.29%)	(2.79%)	(3.05%)	(3.05%)	(3.16%)	(3.13%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses		1.15%	1.90%	1.15%	1.40%	1.90%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Number of years you own your shares ($)

Expense Example Legg Mason Target Retirement 2030 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,630	2,579	4,965
Class C	293	1,262	2,327	4,972
Class FI	117	944	1,789	3,981
Class R	143	1,070	2,007	4,396
Class R1	193	1,214	2,236	4,796
Class I	87	931	1,791	4,018
Class IS	77	895	1,732	3,907

Number of years you own your shares ($)

Expense Example, No Redemption Legg Mason Target Retirement 2030 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,630	2,579	4,965
Class C	193	1,262	2,327	4,972
Class FI	117	944	1,789	3,981
Class R	143	1,070	2,007	4,396
Class R1	193	1,214	2,236	4,796
Class I	87	931	1,791	4,018
Class IS	77	895	1,732	3,907

Portfolio turnover.

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 49% of the average value of its portfolio.

Principal investment strategies

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2030. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2030, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement 2030	73	%	27	%	0	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2045, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2045. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Certain risks

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 33% Russell 1000 Index, 27% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 12% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 11% Barclays U.S. Aggregate Index (an index of fixed income securities), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index, 3% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets), 3% MSCI Emerging Markets Index and 1% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http:/www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Total returns (before taxes) (%)

Calendar Years ended December 31

Best quarter
(06/30/2009): 18.46

Worst quarter
(09/30/2011): (14.19)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 5.11

Average annual total returns (for periods ended December 31, 2012) (%)

Average Annual Total Returns Legg Mason Target Retirement 2030	1 year	Since inception	Inception date
Class C	13.47%	2.96%	Aug. 29, 2008
Class C Return after taxes on distributions	13.01%	2.43%	Aug. 29, 2008
Class C Return after taxes on distributions and sale of fund shares	8.76%	2.20%	Aug. 29, 2008
Class A	8.75%	2.32%	Aug. 29, 2008
Class FI	15.34%	3.73%	Aug. 29, 2008
Class R	15.05%	3.47%	Aug. 29, 2008
Class I	15.69%	4.04%	Aug. 29, 2008
Dow Jones Target 2030 Index (reflects no deduction for fees, expenses or taxes)	12.56%	5.07%
Target Retirement 2030 Composite Index (reflects no deduction for fees, expenses or taxes)	14.77%	4.44%

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[1] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[2] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[3] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

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Legg Mason Target Retirement 2035

Legg Mason Target Retirement 2035

Investment objectives

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

From the five years before until the five years after the fund’s target retirement date of 2035 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Fees and expenses of the fund

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees Legg Mason Target Retirement 2035 (USD $)		Class A		Class C	Class FI	Class R	Class R1	Class I	Class IS
Maximum sales charge (load) imposed on purchases (as a % of offering price)		5.75%		none	none	none	none	none	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)		none	[1]	1.00%	none	none	none	none	none
Small account fee ($)	[2]	15		15	none	none	none	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Annual Fund Operating Expenses Legg Mason Target Retirement 2035		Class A	Class C	Class FI	Class R	Class R1	Class I	Class IS
Management fees		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and service (12b-1) fees		0.25%	1.00%	0.25%	0.50%	1.00%	none	none
Other expenses	[1]	3.76%	3.67%	3.20%	3.48%	3.48%	3.36%	3.28%
Acquired fund fees and expenses (fees and expenses of underlying funds)		0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%
Total annual fund operating expenses	[2]	4.70%	5.36%	4.14%	4.67%	5.17%	4.05%	3.97%
Fees waived and/or expenses reimbursed	[3]	(3.55%)	(3.46%)	(2.99%)	(3.27%)	(3.27%)	(3.20%)	(3.22%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses		1.15%	1.90%	1.15%	1.40%	1.90%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Number of years you own your shares ($)

Expense Example Legg Mason Target Retirement 2035 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,608	2,536	4,881
Class C	293	1,295	2,389	5,089
Class FI	117	985	1,867	4,140
Class R	143	1,114	2,091	4,563
Class R1	193	1,258	2,319	4,954
Class I	87	939	1,807	4,050
Class IS	77	913	1,767	3,979

Number of years you own your shares ($)

Expense Example, No Redemption Legg Mason Target Retirement 2035 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,608	2,536	4,881
Class C	193	1,295	2,389	5,089
Class FI	117	985	1,867	4,140
Class R	143	1,114	2,091	4,563
Class R1	193	1,258	2,319	4,954
Class I	87	939	1,807	4,050
Class IS	77	913	1,767	3,979

Portfolio turnover.

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 52% of the average value of its portfolio.

Principal investment strategies

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation—and investment styles. The fund is designed for investors expecting to retire around 2035. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2035, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds	Fixed Income Funds	Inflation-Hedging Funds
Target Retirement 2035	81%	19%	0%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2050, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Dynamic Risk Management attempts to limit losses by allocating fund assets away from equity and long-term fixed income funds. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2050. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Certain risks

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 41% Russell 1000 Index, 28% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 7% Barclays U.S. Aggregate Index (an index of fixed income securities), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets), 5% Russell 2000 Index, 5% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 2% MSCI Emerging Markets Index and 2% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Total returns (before taxes) (%)

Calender Years ended December 31

Best quarter
(06/30/2009): 19.44

Worst quarter
(09/30/2011): (15.69)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 6.03

Average annual total returns (for periods ended December 31, 2012) (%)

Average Annual Total Returns Legg Mason Target Retirement 2035	1 year	Since inception	Inception date
Class C	14.12%	2.32%	Aug. 29, 2008
Class C Return after taxes on distributions	13.70%	1.89%	Aug. 29, 2008
Class C Return after taxes on distributions and sale of fund shares	9.17%	1.71%	Aug. 29, 2008
Class A	9.32%	1.68%	Aug. 29, 2008
Class FI	16.00%	3.06%	Aug. 29, 2008
Class R	15.60%	2.80%	Aug. 29, 2008
Class I	16.35%	3.37%	Aug. 29, 2008
Dow Jones Target 2035 Index (reflects no deduction for fees, expenses or taxes)	13.92%	4.97%
Target Retirement 2035 Composite Index (reflects no deduction for fees, expenses or taxes)	16.20%	4.39%

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[1] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[2] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[3] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

LEGG MASON PARTNERS EQUITY TRUST

Prospectus Date

rr_ProspectusDate

Jun. 01, 2013

Legg Mason Target Retirement 2040

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Legg Mason Target Retirement 2040

Objective [Heading]

rr_ObjectiveHeading

Investment objectives

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

From the five years before until five years after the fund’s target retirement date of 2040 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses of the fund

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

December 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover.

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 48% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

48.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

25,000

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

“Other expenses” are estimated for the current fiscal year. Actual expenses may differ from estimates.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund’s shareholder reports, because the ratios in the financial highlights tables reflect the fund’s operating expenses and do not include acquired fund fees and expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Number of years you own your shares ($)

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

Number of years you own your shares ($)

Strategy [Heading]

rr_StrategyHeading

Principal investment strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2040. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2040, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds	Fixed Income Funds	Inflation-Hedging Funds
Target Retirement 2040	92%	8%	0%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:





During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2055, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Dynamic Risk Management attempts to limit losses by allocating fund assets away from equity and long-term fixed income funds. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2055. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Risk [Heading]

rr_RiskHeading

Certain risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 52% Russell 1000 Index, 28% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets), 5% Russell 2000 Index, 3% Barclays U.S. Aggregate Index (an index of fixed income securities) and 2% MSCI Emerging Markets Index. Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-877-721-1926

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class)

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Total returns (before taxes) (%)

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Calendar Years ended December 31

Best quarter
(06/30/2009): 19.66

Worst quarter
(09/30/2011): (16.03)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 7.01

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns (for periods ended December 31, 2012) (%)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Legg Mason Target Retirement 2040 | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.88%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.82%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.67%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

685

3 years

rr_ExpenseExampleYear03

1,630

5 years

rr_ExpenseExampleYear05

2,579

10 years

rr_ExpenseExampleYear10

4,965

1 year

rr_ExpenseExampleNoRedemptionYear01

685

3 years

rr_ExpenseExampleNoRedemptionYear03

1,630

5 years

rr_ExpenseExampleNoRedemptionYear05

2,579

10 years

rr_ExpenseExampleNoRedemptionYear10

4,965

1 year

rr_AverageAnnualReturnYear01

9.09%

Since inception

rr_AverageAnnualReturnSinceInception

1.75%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2040 | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

1.00%

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.65%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.34%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.44%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

293

3 years

rr_ExpenseExampleYear03

1,291

5 years

rr_ExpenseExampleYear05

2,381

10 years

rr_ExpenseExampleYear10

5,074

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,291

5 years

rr_ExpenseExampleNoRedemptionYear05

2,381

10 years

rr_ExpenseExampleNoRedemptionYear10

5,074

2009

rr_AnnualReturn2009

28.44%

2010

rr_AnnualReturn2010

13.78%

2011

rr_AnnualReturn2011

(3.86%)

2012

rr_AnnualReturn2012

14.78%

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date return as of the most recent calendar quarter

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

7.01%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

19.66%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(16.03%)

1 year

rr_AverageAnnualReturnYear01

13.78%

Since inception

rr_AverageAnnualReturnSinceInception

2.39%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2040 | Class FI

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.10%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.04%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.89%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

117

3 years

rr_ExpenseExampleYear03

965

5 years

rr_ExpenseExampleYear05

1,829

10 years

rr_ExpenseExampleYear10

4,061

1 year

rr_ExpenseExampleNoRedemptionYear01

117

3 years

rr_ExpenseExampleNoRedemptionYear03

965

5 years

rr_ExpenseExampleNoRedemptionYear05

1,829

10 years

rr_ExpenseExampleNoRedemptionYear10

4,061

1 year

rr_AverageAnnualReturnYear01

15.74%

Since inception

rr_AverageAnnualReturnSinceInception

3.17%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2040 | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

3.06%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.25%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.85%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.40%

1 year

rr_ExpenseExampleYear01

143

3 years

rr_ExpenseExampleYear03

1,030

5 years

rr_ExpenseExampleYear05

1,931

10 years

rr_ExpenseExampleYear10

4,242

1 year

rr_ExpenseExampleNoRedemptionYear01

143

3 years

rr_ExpenseExampleNoRedemptionYear03

1,030

5 years

rr_ExpenseExampleNoRedemptionYear05

1,931

10 years

rr_ExpenseExampleNoRedemptionYear10

4,242

1 year

rr_AverageAnnualReturnYear01

15.47%

Since inception

rr_AverageAnnualReturnSinceInception

2.90%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2040 | Class R1

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.06%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.75%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.85%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

193

3 years

rr_ExpenseExampleYear03

1,175

5 years

rr_ExpenseExampleYear05

2,162

10 years

rr_ExpenseExampleYear10

4,650

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,175

5 years

rr_ExpenseExampleNoRedemptionYear05

2,162

10 years

rr_ExpenseExampleNoRedemptionYear10

4,650

Legg Mason Target Retirement 2040 | Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.41%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.10%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.25%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.85%

1 year

rr_ExpenseExampleYear01

87

3 years

rr_ExpenseExampleYear03

949

5 years

rr_ExpenseExampleYear05

1,827

10 years

rr_ExpenseExampleYear10

4,092

1 year

rr_ExpenseExampleNoRedemptionYear01

87

3 years

rr_ExpenseExampleNoRedemptionYear03

949

5 years

rr_ExpenseExampleNoRedemptionYear05

1,827

10 years

rr_ExpenseExampleNoRedemptionYear10

4,092

1 year

rr_AverageAnnualReturnYear01

16.01%

Since inception

rr_AverageAnnualReturnSinceInception

3.45%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2040 | Class IS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.29%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.98%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.23%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.75%

1 year

rr_ExpenseExampleYear01

77

3 years

rr_ExpenseExampleYear03

915

5 years

rr_ExpenseExampleYear05

1,771

10 years

rr_ExpenseExampleYear10

3,987

1 year

rr_ExpenseExampleNoRedemptionYear01

77

3 years

rr_ExpenseExampleNoRedemptionYear03

915

5 years

rr_ExpenseExampleNoRedemptionYear05

1,771

10 years

rr_ExpenseExampleNoRedemptionYear10

3,987

Legg Mason Target Retirement 2040 | Return after taxes on distributions | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

13.44%

Since inception

rr_AverageAnnualReturnSinceInception

2.05%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2040 | Return after taxes on distributions and sale of fund shares | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

8.95%

Since inception

rr_AverageAnnualReturnSinceInception

1.83%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2040 | Dow Jones Target 2040 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

14.88%

Since inception

rr_AverageAnnualReturnSinceInception

4.95%

Legg Mason Target Retirement 2040 | Target Retirement 2040 Composite Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

16.93%

Since inception

rr_AverageAnnualReturnSinceInception

4.57%

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[3] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[4] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[5] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

LEGG MASON PARTNERS EQUITY TRUST

Prospectus Date

rr_ProspectusDate

Jun. 01, 2013

Legg Mason Target Retirement 2025

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Legg Mason Target Retirement 2025

Objective [Heading]

rr_ObjectiveHeading

Investment objectives

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

From the five years before until the five years after the fund’s target retirement date of 2025 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses of the fund

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

December 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover.

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 30% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

30.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

25,000

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

“Other expenses” are estimated for the current fiscal year. Actual expenses may differ from estimates.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund’s shareholder reports, because the ratios in the financial highlights tables reflect the fund’s operating expenses and do not include acquired fund fees and expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Number of years you own your shares ($)

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

Number of years you own your shares ($)

Strategy [Heading]

rr_StrategyHeading

Principal investment strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2025. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2025, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement 2025	64	%	31	%	5	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2040, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2040. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Risk [Heading]

rr_RiskHeading

Certain risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 28% Russell 1000 Index, 26% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 16% Barclays U.S. Aggregate Index (an index of fixed income securities), 15% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index, 4% MSCI Emerging Markets Index, 1% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets) and 1% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-877-721-1926

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class)

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Total returns (before taxes) (%)

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Calendar Years ended December 31

Best quarter
(06/30/2009): 18.49

Worst quarter
(09/30/2011): (12.96)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 4.43

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns (for periods ended December 31, 2012) (%)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Legg Mason Target Retirement 2025 | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

2.74%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.60%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.69%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.54%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

685

3 years

rr_ExpenseExampleYear03

1,417

5 years

rr_ExpenseExampleYear05

2,168

10 years

rr_ExpenseExampleYear10

4,133

1 year

rr_ExpenseExampleNoRedemptionYear01

685

3 years

rr_ExpenseExampleNoRedemptionYear03

1,417

5 years

rr_ExpenseExampleNoRedemptionYear05

2,168

10 years

rr_ExpenseExampleNoRedemptionYear10

4,133

1 year

rr_AverageAnnualReturnYear01

8.02%

Since inception

rr_AverageAnnualReturnSinceInception

3.01%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2025 | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

1.00%

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

2.63%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.60%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.33%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.43%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

293

3 years

rr_ExpenseExampleYear03

1,092

5 years

rr_ExpenseExampleYear05

2,003

10 years

rr_ExpenseExampleYear10

4,333

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,092

5 years

rr_ExpenseExampleNoRedemptionYear05

2,003

10 years

rr_ExpenseExampleNoRedemptionYear10

4,333

2009

rr_AnnualReturn2009

26.36%

2010

rr_AnnualReturn2010

13.30%

2011

rr_AnnualReturn2011

(2.62%)

2012

rr_AnnualReturn2012

13.81%

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date return as of the most recent calendar quarter

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

4.43%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

18.49%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(12.96%)

1 year

rr_AverageAnnualReturnYear01

12.81%

Since inception

rr_AverageAnnualReturnSinceInception

3.67%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2025 | Class FI

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

2.15%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.60%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.10%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(1.95%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

117

3 years

rr_ExpenseExampleYear03

773

5 years

rr_ExpenseExampleYear05

1,454

10 years

rr_ExpenseExampleYear10

3,274

1 year

rr_ExpenseExampleNoRedemptionYear01

117

3 years

rr_ExpenseExampleNoRedemptionYear03

773

5 years

rr_ExpenseExampleNoRedemptionYear05

1,454

10 years

rr_ExpenseExampleNoRedemptionYear10

3,274

1 year

rr_AverageAnnualReturnYear01

14.77%

Since inception

rr_AverageAnnualReturnSinceInception

4.45%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2025 | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

2.62%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.60%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.82%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.42%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.40%

1 year

rr_ExpenseExampleYear01

143

3 years

rr_ExpenseExampleYear03

944

5 years

rr_ExpenseExampleYear05

1,764

10 years

rr_ExpenseExampleYear10

3,899

1 year

rr_ExpenseExampleNoRedemptionYear01

143

3 years

rr_ExpenseExampleNoRedemptionYear03

944

5 years

rr_ExpenseExampleNoRedemptionYear05

1,764

10 years

rr_ExpenseExampleNoRedemptionYear10

3,899

1 year

rr_AverageAnnualReturnYear01

14.38%

Since inception

rr_AverageAnnualReturnSinceInception

4.19%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2025 | Class R1

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

2.62%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.60%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.32%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.42%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

193

3 years

rr_ExpenseExampleYear03

1,090

5 years

rr_ExpenseExampleYear05

1,999

10 years

rr_ExpenseExampleYear10

4,326

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,090

5 years

rr_ExpenseExampleNoRedemptionYear05

1,999

10 years

rr_ExpenseExampleNoRedemptionYear10

4,326

Legg Mason Target Retirement 2025 | Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

2.53%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.60%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.23%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.38%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.85%

1 year

rr_ExpenseExampleYear01

87

3 years

rr_ExpenseExampleYear03

771

5 years

rr_ExpenseExampleYear05

1,481

10 years

rr_ExpenseExampleYear10

3,367

1 year

rr_ExpenseExampleNoRedemptionYear01

87

3 years

rr_ExpenseExampleNoRedemptionYear03

771

5 years

rr_ExpenseExampleNoRedemptionYear05

1,481

10 years

rr_ExpenseExampleNoRedemptionYear10

3,367

1 year

rr_AverageAnnualReturnYear01

14.94%

Since inception

rr_AverageAnnualReturnSinceInception

4.74%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2025 | Class IS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

2.41%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.60%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.11%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.36%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.75%

1 year

rr_ExpenseExampleYear01

77

3 years

rr_ExpenseExampleYear03

737

5 years

rr_ExpenseExampleYear05

1,423

10 years

rr_ExpenseExampleYear10

3,254

1 year

rr_ExpenseExampleNoRedemptionYear01

77

3 years

rr_ExpenseExampleNoRedemptionYear03

737

5 years

rr_ExpenseExampleNoRedemptionYear05

1,423

10 years

rr_ExpenseExampleNoRedemptionYear10

3,254

Legg Mason Target Retirement 2025 | Return after taxes on distributions | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

12.37%

Since inception

rr_AverageAnnualReturnSinceInception

3.09%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2025 | Return after taxes on distributions and sale of fund shares | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

8.34%

Since inception

rr_AverageAnnualReturnSinceInception

2.78%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2025 | Dow Jones Target 2025 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

10.94%

Since inception

rr_AverageAnnualReturnSinceInception

5.18%

Legg Mason Target Retirement 2025 | Target Retirement 2025 Composite Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

13.65%

Since inception

rr_AverageAnnualReturnSinceInception

4.65%

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[3] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[4] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[5] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

LEGG MASON PARTNERS EQUITY TRUST

Prospectus Date

rr_ProspectusDate

Jun. 01, 2013

Legg Mason Target Retirement Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Legg Mason Target Retirement Fund

Objective [Heading]

rr_ObjectiveHeading

Investment objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses of the fund

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

December 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover.

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 47% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

47.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

25,000

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

“Other expenses” are estimated for the current fiscal year. Actual expenses may differ from estimates.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund’s shareholder reports, because the ratios in the financial highlights tables reflect the fund’s operating expenses and do not include acquired fund fees and expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Number of years you own your shares ($)

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

Number of years you own your shares ($)

Strategy [Heading]

rr_StrategyHeading

Principal investment strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objective by investing in a combination of underlying funds representing a variety of broad asset classes—equity (including real estate-related funds), fixed income and inflation-hedging—and investment styles.

The fund maintains a static Target Allocation. The following table details the Target Allocation of the fund among broad asset classes.

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement Fund	33	%	62	%	5	%

The Target Allocation is a “neutral” allocation, which does not reflect tactical decisions made by Legg Mason Global Asset Allocation, LLC (“LMGAA”), the subadviser, to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Ordinarily, the fund’s investment in equity, fixed income or inflation-hedging funds is not expected to vary from the Target Allocation for that asset class by more than plus/minus 10%. Beyond that range, LMGAA will generally rebalance the fund.

Risk [Heading]

rr_RiskHeading

Certain risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objective. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of the underlying Legg Mason and Western Asset funds and is affiliated with the manager of the underlying Royce funds. In addition, the fund may invest in certain underlying funds for which LMGAA serves as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager and LMGAA fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets to those funds for which the fees paid to the manager or LMGAA are higher than the fees paid by other underlying funds or to those funds for which LMGAA serves as adviser. However, the fund’s Board of Trustees believes the fund has been structured to mitigate these concerns.

Allocation risk. The fund’s ability to achieve its investment objective depends upon the subadvisers’ skill in determining the fund’s asset class allocation and in selecting the best mix of underlying funds. The value of your investment may decrease if the subadvisers’ judgment about the attractiveness, value or market trends affecting a particular asset class, investment style or technique, underlying fund or other issuer is incorrect.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income or inflation-hedging investments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a stock can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s portfolio managers believe appropriate and may offer greater potential for losses.

Liquidity risk. Some assets held by an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets may also be difficult to value. If an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to net asset value. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to the Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East (“EAFE”) Index, the Barclays U.S. Aggregate Index and a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 42% Barclays U.S. Aggregate Index (an index of fixed income securities), 15% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 14% MSCI EAFE Index, 8% Russell 1000 Index, 8% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index and 3% MSCI Emerging Markets Index.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-877-721-1926

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class)

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Total returns (before taxes) (%)

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Calendar Years ended December 31

Best quarter
(06/30/2009): 16.89

Worst quarter
(03/31/2009): (8.05)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 1.95

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns (for periods ended December 31, 2012) (%)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Legg Mason Target Retirement Fund | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.97%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.55%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.87%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.72%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

685

3 years

rr_ExpenseExampleYear03

1,640

5 years

rr_ExpenseExampleYear05

2,597

10 years

rr_ExpenseExampleYear10

5,000

1 year

rr_ExpenseExampleNoRedemptionYear01

685

3 years

rr_ExpenseExampleNoRedemptionYear03

1,640

5 years

rr_ExpenseExampleNoRedemptionYear05

2,597

10 years

rr_ExpenseExampleNoRedemptionYear10

5,000

1 year

rr_AverageAnnualReturnYear01

5.24%

Since inception

rr_AverageAnnualReturnSinceInception

5.84%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement Fund | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

1.00%

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

4.01%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.55%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.66%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.76%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

293

3 years

rr_ExpenseExampleYear03

1,353

5 years

rr_ExpenseExampleYear05

2,497

10 years

rr_ExpenseExampleYear10

5,292

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,353

5 years

rr_ExpenseExampleNoRedemptionYear05

2,497

10 years

rr_ExpenseExampleNoRedemptionYear10

5,292

2009

rr_AnnualReturn2009

26.67%

2010

rr_AnnualReturn2010

13.28%

2011

rr_AnnualReturn2011

1.12%

2012

rr_AnnualReturn2012

10.78%

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date return as of the most recent calendar quarter

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

1.95%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

16.89%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2009

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(8.05%)

1 year

rr_AverageAnnualReturnYear01

9.78%

Since inception

rr_AverageAnnualReturnSinceInception

6.49%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement Fund | Class FI

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.63%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.55%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.53%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.38%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

117

3 years

rr_ExpenseExampleYear03

1,063

5 years

rr_ExpenseExampleYear05

2,017

10 years

rr_ExpenseExampleYear10

4,442

1 year

rr_ExpenseExampleNoRedemptionYear01

117

3 years

rr_ExpenseExampleNoRedemptionYear03

1,063

5 years

rr_ExpenseExampleNoRedemptionYear05

2,017

10 years

rr_ExpenseExampleNoRedemptionYear10

4,442

1 year

rr_AverageAnnualReturnYear01

11.63%

Since inception

rr_AverageAnnualReturnSinceInception

7.28%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement Fund | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

3.27%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.55%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.42%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.02%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.40%

1 year

rr_ExpenseExampleYear01

143

3 years

rr_ExpenseExampleYear03

1,064

5 years

rr_ExpenseExampleYear05

1,996

10 years

rr_ExpenseExampleYear10

4,373

1 year

rr_ExpenseExampleNoRedemptionYear01

143

3 years

rr_ExpenseExampleNoRedemptionYear03

1,064

5 years

rr_ExpenseExampleNoRedemptionYear05

1,996

10 years

rr_ExpenseExampleNoRedemptionYear10

4,373

1 year

rr_AverageAnnualReturnYear01

11.25%

Since inception

rr_AverageAnnualReturnSinceInception

7.01%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement Fund | Class R1

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.27%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.55%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.92%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.02%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

193

3 years

rr_ExpenseExampleYear03

1,208

5 years

rr_ExpenseExampleYear05

2,225

10 years

rr_ExpenseExampleYear10

4,774

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,208

5 years

rr_ExpenseExampleNoRedemptionYear05

2,225

10 years

rr_ExpenseExampleNoRedemptionYear10

4,774

Legg Mason Target Retirement Fund | Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.55%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.55%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.20%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.35%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.85%

1 year

rr_ExpenseExampleYear01

87

3 years

rr_ExpenseExampleYear03

969

5 years

rr_ExpenseExampleYear05

1,865

10 years

rr_ExpenseExampleYear10

4,168

1 year

rr_ExpenseExampleNoRedemptionYear01

87

3 years

rr_ExpenseExampleNoRedemptionYear03

969

5 years

rr_ExpenseExampleNoRedemptionYear05

1,865

10 years

rr_ExpenseExampleNoRedemptionYear10

4,168

1 year

rr_AverageAnnualReturnYear01

11.98%

Since inception

rr_AverageAnnualReturnSinceInception

7.61%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement Fund | Class IS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.55%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.55%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.20%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.45%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.75%

1 year

rr_ExpenseExampleYear01

77

3 years

rr_ExpenseExampleYear03

960

5 years

rr_ExpenseExampleYear05

1,857

10 years

rr_ExpenseExampleYear10

4,163

1 year

rr_ExpenseExampleNoRedemptionYear01

77

3 years

rr_ExpenseExampleNoRedemptionYear03

960

5 years

rr_ExpenseExampleNoRedemptionYear05

1,857

10 years

rr_ExpenseExampleNoRedemptionYear10

4,163

Legg Mason Target Retirement Fund | Return after taxes on distributions | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

9.28%

Since inception

rr_AverageAnnualReturnSinceInception

5.51%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement Fund | Return after taxes on distributions and sale of fund shares | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

6.38%

Since inception

rr_AverageAnnualReturnSinceInception

4.98%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement Fund | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

16.42%

Since inception

rr_AverageAnnualReturnSinceInception

4.99%

Legg Mason Target Retirement Fund | MSCI EAFE Index (Gross) (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

17.90%

Since inception

rr_AverageAnnualReturnSinceInception

0.51%

Legg Mason Target Retirement Fund | Barclays U.S. Aggregate Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

4.22%

Since inception

rr_AverageAnnualReturnSinceInception

6.41%

Legg Mason Target Retirement Fund | Target Retirement Fund Composite Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

9.93%

Since inception

rr_AverageAnnualReturnSinceInception

6.43%

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[3] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[4] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[5] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

LEGG MASON PARTNERS EQUITY TRUST

Prospectus Date

rr_ProspectusDate

Jun. 01, 2013

Legg Mason Target Retirement 2015

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Legg Mason Target Retirement 2015

Objective [Heading]

rr_ObjectiveHeading

Investment objectives

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

The fund will seek to reduce volatility as a secondary objective until five years after the fund’s target retirement date of 2015 (the “Dynamic Rebalancing Period”).

Expense [Heading]

rr_ExpenseHeading

Fees and expenses of the fund

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

December 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover.

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 202% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

202.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

25,000

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

“Other expenses” are estimated for the current fiscal year. Actual expenses may differ from estimates.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund’s shareholder reports, because the ratios in the financial highlights tables reflect the fund’s operating expenses and do not include acquired fund fees and expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Number of years you own your shares ($)

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

Number of years you own your shares ($)

Strategy [Heading]

rr_StrategyHeading

Principal investment strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income, inflation-hedging and short-term defensive instruments—and investment styles. The fund is designed for investors expecting to retire around 2015. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2015, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds			Fixed Income Funds			Inflation-Hedging Funds
Target Retirement 2015		53	%		42	%		5	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2030, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

The fund is currently in its Dynamic Rebalancing Period and, at times, may not follow the Target Allocation indicated by the glide path. LMGAA will revert to managing this fund according to the Target Allocation at the end of the Dynamic Rebalancing Period on December 31, 2019.

Dynamic risk management. The Dynamic Risk Management strategy seeks to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets. As of January 31, 2013, the fund had 0% of its net assets allocated to short-term defensive instruments.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”), based on a formula that takes into account the fund’s current NAV, macro-economic conditions and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy seeks to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. As of January 31, 2013, the fund had less than 1% of its net assets allocated to this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2030. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Risk [Heading]

rr_RiskHeading

Certain risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 27% Barclays U.S. Aggregate Index (an index of fixed income securities), 22% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 19% Russell 1000 Index, 15% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index, 4% MSCI Emerging Markets Index and 3% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-877-721-1926

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class)

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Total returns (before taxes) (%)

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Calendar Years ended December 31

Best quarter
(06/30/2009): 18.05

Worst quarter
(09/30/2011): (10.63)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 3.00

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns (for periods ended December 31, 2012) (%)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

The fund’s investment objectives and investment strategies were changed in August 2011 and its investment strategies were further revised in November 2011. The fund’s historical performance for the periods prior to August 1, 2011 and November 21, 2011 is based on the fund’s former investment objectives and strategies.

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Legg Mason Target Retirement 2015 | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

4.27%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.57%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.19%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(4.04%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

685

3 years

rr_ExpenseExampleYear03

1,700

5 years

rr_ExpenseExampleYear05

2,711

10 years

rr_ExpenseExampleYear10

5,221

1 year

rr_ExpenseExampleNoRedemptionYear01

685

3 years

rr_ExpenseExampleNoRedemptionYear03

1,700

5 years

rr_ExpenseExampleNoRedemptionYear05

2,711

10 years

rr_ExpenseExampleNoRedemptionYear10

5,221

1 year

rr_AverageAnnualReturnYear01

1.77%

Since inception

rr_AverageAnnualReturnSinceInception

1.64%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2015 | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

1.00%

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

4.06%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.57%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.73%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.83%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

293

3 years

rr_ExpenseExampleYear03

1,366

5 years

rr_ExpenseExampleYear05

2,522

10 years

rr_ExpenseExampleYear10

5,338

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,366

5 years

rr_ExpenseExampleNoRedemptionYear05

2,522

10 years

rr_ExpenseExampleNoRedemptionYear10

5,338

2009

rr_AnnualReturn2009

25.96%

2010

rr_AnnualReturn2010

13.11%

2011

rr_AnnualReturn2011

(5.57%)

2012

rr_AnnualReturn2012

7.16%

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date return as of the most recent calendar quarter

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

3.00%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

18.05%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(10.63%)

1 year

rr_AverageAnnualReturnYear01

6.16%

Since inception

rr_AverageAnnualReturnSinceInception

2.28%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2015 | Class FI

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.61%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.57%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.53%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.38%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

117

3 years

rr_ExpenseExampleYear03

1,063

5 years

rr_ExpenseExampleYear05

2,017

10 years

rr_ExpenseExampleYear10

4,442

1 year

rr_ExpenseExampleNoRedemptionYear01

117

3 years

rr_ExpenseExampleNoRedemptionYear03

1,063

5 years

rr_ExpenseExampleNoRedemptionYear05

2,017

10 years

rr_ExpenseExampleNoRedemptionYear10

4,442

1 year

rr_AverageAnnualReturnYear01

7.98%

Since inception

rr_AverageAnnualReturnSinceInception

3.06%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2015 | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

3.61%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.57%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.78%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.38%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.40%

1 year

rr_ExpenseExampleYear01

143

3 years

rr_ExpenseExampleYear03

1,136

5 years

rr_ExpenseExampleYear05

2,133

10 years

rr_ExpenseExampleYear10

4,644

1 year

rr_ExpenseExampleNoRedemptionYear01

143

3 years

rr_ExpenseExampleNoRedemptionYear03

1,136

5 years

rr_ExpenseExampleNoRedemptionYear05

2,133

10 years

rr_ExpenseExampleNoRedemptionYear10

4,644

1 year

rr_AverageAnnualReturnYear01

7.70%

Since inception

rr_AverageAnnualReturnSinceInception

2.79%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2015 | Class R1

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.61%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.57%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.28%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.38%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

193

3 years

rr_ExpenseExampleYear03

1,279

5 years

rr_ExpenseExampleYear05

2,359

10 years

rr_ExpenseExampleYear10

5,033

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,279

5 years

rr_ExpenseExampleNoRedemptionYear05

2,359

10 years

rr_ExpenseExampleNoRedemptionYear10

5,033

Legg Mason Target Retirement 2015 | Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

4.23%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.57%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.90%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(4.05%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.85%

1 year

rr_ExpenseExampleYear01

87

3 years

rr_ExpenseExampleYear03

1,109

5 years

rr_ExpenseExampleYear05

2,133

10 years

rr_ExpenseExampleYear10

4,702

1 year

rr_ExpenseExampleNoRedemptionYear01

87

3 years

rr_ExpenseExampleNoRedemptionYear03

1,109

5 years

rr_ExpenseExampleNoRedemptionYear05

2,133

10 years

rr_ExpenseExampleNoRedemptionYear10

4,702

1 year

rr_AverageAnnualReturnYear01

8.22%

Since inception

rr_AverageAnnualReturnSinceInception

3.34%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2015 | Class IS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.89%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.57%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.56%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.81%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.75%

1 year

rr_ExpenseExampleYear01

77

3 years

rr_ExpenseExampleYear03

1,032

5 years

rr_ExpenseExampleYear05

1,996

10 years

rr_ExpenseExampleYear10

4,441

1 year

rr_ExpenseExampleNoRedemptionYear01

77

3 years

rr_ExpenseExampleNoRedemptionYear03

1,032

5 years

rr_ExpenseExampleNoRedemptionYear05

1,996

10 years

rr_ExpenseExampleNoRedemptionYear10

4,441

Legg Mason Target Retirement 2015 | Return after taxes on distributions | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

5.85%

Since inception

rr_AverageAnnualReturnSinceInception

1.70%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2015 | Return after taxes on distributions and sale of fund shares | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

4.01%

Since inception

rr_AverageAnnualReturnSinceInception

1.60%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2015 | Dow Jones Target 2015 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

7.65%

Since inception

rr_AverageAnnualReturnSinceInception

5.43%

Legg Mason Target Retirement 2015 | Target Retirement 2015 Composite Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

12.19%

Since inception

rr_AverageAnnualReturnSinceInception

5.11%

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[3] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[4] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[5] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Label

Element

Value

Risk/Return:

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Registrant Name

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LEGG MASON PARTNERS EQUITY TRUST

Prospectus Date

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Jun. 01, 2013

Legg Mason Target Retirement 2035

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

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Legg Mason Target Retirement 2035

Objective [Heading]

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Investment objectives

Objective, Primary [Text Block]

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The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Objective, Secondary [Text Block]

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From the five years before until the five years after the fund’s target retirement date of 2035 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Expense [Heading]

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Fees and expenses of the fund

Expense Narrative [Text Block]

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The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder Fees Caption [Text]

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Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

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Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

December 31, 2014

Portfolio Turnover [Heading]

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Portfolio turnover.

Portfolio Turnover [Text Block]

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The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 52% of the average value of its portfolio.

Portfolio Turnover, Rate

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52.00%

Expense Breakpoint Discounts [Text]

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You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

25,000

Other Expenses, New Fund, Based on Estimates [Text]

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“Other expenses” are estimated for the current fiscal year. Actual expenses may differ from estimates.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

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Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund’s shareholder reports, because the ratios in the financial highlights tables reflect the fund’s operating expenses and do not include acquired fund fees and expenses.

Expense Example [Heading]

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Example

Expense Example Narrative [Text Block]

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This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Number of years you own your shares ($)

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

Number of years you own your shares ($)

Strategy [Heading]

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Principal investment strategies

Strategy Narrative [Text Block]

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The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation—and investment styles. The fund is designed for investors expecting to retire around 2035. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2035, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds	Fixed Income Funds	Inflation-Hedging Funds
Target Retirement 2035	81%	19%	0%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2050, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Dynamic Risk Management attempts to limit losses by allocating fund assets away from equity and long-term fixed income funds. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2050. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Risk [Heading]

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Certain risks

Risk Narrative [Text Block]

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Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Risk Lose Money [Text]

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You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.

Bar Chart and Performance Table [Heading]

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Performance

Performance Narrative [Text Block]

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The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 41% Russell 1000 Index, 28% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 7% Barclays U.S. Aggregate Index (an index of fixed income securities), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets), 5% Russell 2000 Index, 5% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 2% MSCI Emerging Markets Index and 2% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Performance Information Illustrates Variability of Returns [Text]

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The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark.

Performance Availability Phone [Text]

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1-877-721-1926

Performance Availability Website Address [Text]

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http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class)

Performance Past Does Not Indicate Future [Text]

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The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Bar Chart [Heading]

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Total returns (before taxes) (%)

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Calender Years ended December 31

Best quarter
(06/30/2009): 19.44

Worst quarter
(09/30/2011): (15.69)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 6.03

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns (for periods ended December 31, 2012) (%)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Legg Mason Target Retirement 2035 | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.76%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.70%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.55%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

685

3 years

rr_ExpenseExampleYear03

1,608

5 years

rr_ExpenseExampleYear05

2,536

10 years

rr_ExpenseExampleYear10

4,881

1 year

rr_ExpenseExampleNoRedemptionYear01

685

3 years

rr_ExpenseExampleNoRedemptionYear03

1,608

5 years

rr_ExpenseExampleNoRedemptionYear05

2,536

10 years

rr_ExpenseExampleNoRedemptionYear10

4,881

1 year

rr_AverageAnnualReturnYear01

9.32%

Since inception

rr_AverageAnnualReturnSinceInception

1.68%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2035 | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

1.00%

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.67%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.36%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.46%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

293

3 years

rr_ExpenseExampleYear03

1,295

5 years

rr_ExpenseExampleYear05

2,389

10 years

rr_ExpenseExampleYear10

5,089

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,295

5 years

rr_ExpenseExampleNoRedemptionYear05

2,389

10 years

rr_ExpenseExampleNoRedemptionYear10

5,089

2009

rr_AnnualReturn2009

26.94%

2010

rr_AnnualReturn2010

13.55%

2011

rr_AnnualReturn2011

(3.83%)

2012

rr_AnnualReturn2012

15.12%

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date return as of the most recent calendar quarter

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.03%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

19.44%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(15.69%)

1 year

rr_AverageAnnualReturnYear01

14.12%

Since inception

rr_AverageAnnualReturnSinceInception

2.32%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2035 | Class FI

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.20%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.14%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.99%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

117

3 years

rr_ExpenseExampleYear03

985

5 years

rr_ExpenseExampleYear05

1,867

10 years

rr_ExpenseExampleYear10

4,140

1 year

rr_ExpenseExampleNoRedemptionYear01

117

3 years

rr_ExpenseExampleNoRedemptionYear03

985

5 years

rr_ExpenseExampleNoRedemptionYear05

1,867

10 years

rr_ExpenseExampleNoRedemptionYear10

4,140

1 year

rr_AverageAnnualReturnYear01

16.00%

Since inception

rr_AverageAnnualReturnSinceInception

3.06%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2035 | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

3.48%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.67%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.27%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.40%

1 year

rr_ExpenseExampleYear01

143

3 years

rr_ExpenseExampleYear03

1,114

5 years

rr_ExpenseExampleYear05

2,091

10 years

rr_ExpenseExampleYear10

4,563

1 year

rr_ExpenseExampleNoRedemptionYear01

143

3 years

rr_ExpenseExampleNoRedemptionYear03

1,114

5 years

rr_ExpenseExampleNoRedemptionYear05

2,091

10 years

rr_ExpenseExampleNoRedemptionYear10

4,563

1 year

rr_AverageAnnualReturnYear01

15.60%

Since inception

rr_AverageAnnualReturnSinceInception

2.80%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2035 | Class R1

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.48%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.17%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.27%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

193

3 years

rr_ExpenseExampleYear03

1,258

5 years

rr_ExpenseExampleYear05

2,319

10 years

rr_ExpenseExampleYear10

4,954

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,258

5 years

rr_ExpenseExampleNoRedemptionYear05

2,319

10 years

rr_ExpenseExampleNoRedemptionYear10

4,954

Legg Mason Target Retirement 2035 | Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.36%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.05%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.20%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.85%

1 year

rr_ExpenseExampleYear01

87

3 years

rr_ExpenseExampleYear03

939

5 years

rr_ExpenseExampleYear05

1,807

10 years

rr_ExpenseExampleYear10

4,050

1 year

rr_ExpenseExampleNoRedemptionYear01

87

3 years

rr_ExpenseExampleNoRedemptionYear03

939

5 years

rr_ExpenseExampleNoRedemptionYear05

1,807

10 years

rr_ExpenseExampleNoRedemptionYear10

4,050

1 year

rr_AverageAnnualReturnYear01

16.35%

Since inception

rr_AverageAnnualReturnSinceInception

3.37%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2035 | Class IS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.28%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.97%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.22%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.75%

1 year

rr_ExpenseExampleYear01

77

3 years

rr_ExpenseExampleYear03

913

5 years

rr_ExpenseExampleYear05

1,767

10 years

rr_ExpenseExampleYear10

3,979

1 year

rr_ExpenseExampleNoRedemptionYear01

77

3 years

rr_ExpenseExampleNoRedemptionYear03

913

5 years

rr_ExpenseExampleNoRedemptionYear05

1,767

10 years

rr_ExpenseExampleNoRedemptionYear10

3,979

Legg Mason Target Retirement 2035 | Return after taxes on distributions | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

13.70%

Since inception

rr_AverageAnnualReturnSinceInception

1.89%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2035 | Return after taxes on distributions and sale of fund shares | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

9.17%

Since inception

rr_AverageAnnualReturnSinceInception

1.71%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2035 | Dow Jones Target 2035 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

13.92%

Since inception

rr_AverageAnnualReturnSinceInception

4.97%

Legg Mason Target Retirement 2035 | Target Retirement 2035 Composite Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

16.20%

Since inception

rr_AverageAnnualReturnSinceInception

4.39%

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[3] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[4] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[5] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Legg Mason Target Retirement 2045

Legg Mason Target Retirement 2045

Investment objectives

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

From the five years before until the five years after the fund’s target retirement date of 2045 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Fees and expenses of the fund

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees Legg Mason Target Retirement 2045 (USD $)		Class A		Class C	Class FI	Class R	Class R1	Class I	Class IS
Maximum sales charge (load) imposed on purchases (as a % of offering price)		5.75%		none	none	none	none	none	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)		none	[1]	1.00%	none	none	none	none	none
Small account fee ($)	[2]	15		15	none	none	none	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Annual Fund Operating Expenses Legg Mason Target Retirement 2045		Class A	Class C	Class FI	Class R	Class R1	Class I	Class IS
Management fees		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and service (12b-1) fees		0.25%	1.00%	0.25%	0.50%	1.00%	none	none
Other expenses	[1]	5.87%	5.84%	5.01%	4.86%	4.86%	5.49%	5.38%
Acquired fund fees and expenses (fees and expenses of underlying funds)		0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%
Total annual fund operating expenses	[2]	6.81%	7.53%	5.95%	6.05%	6.55%	6.18%	6.07%
Fees waived and/or expenses reimbursed	[3]	(5.66%)	(5.63%)	(4.80%)	(4.65%)	(4.65%)	(5.33%)	(5.32%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses		1.15%	1.90%	1.15%	1.40%	1.90%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Number of years you own your shares ($)

Expense Example Legg Mason Target Retirement 2045 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,995	3,257	6,218
Class C	293	1,707	3,145	6,433
Class FI	117	1,341	2,542	5,446
Class R	143	1,383	2,597	5,523
Class R1	193	1,523	2,811	5,862
Class I	87	1,359	2,601	5,581
Class IS	77	1,329	2,554	5,505

Number of years you own your shares ($)

Expense Example, No Redemption Legg Mason Target Retirement 2045 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,995	3,257	6,218
Class C	193	1,707	3,145	6,433
Class FI	117	1,341	2,542	5,446
Class R	143	1,383	2,597	5,523
Class R1	193	1,523	2,811	5,862
Class I	87	1,359	2,601	5,581
Class IS	77	1,329	2,554	5,505

Portfolio turnover.

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Principal investment strategies

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2045. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2045, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement 2045	94	%	6	%	0	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2060, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2060. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Certain risks

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 51% Russell 1000 Index, 26% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 8% Russell 2000 Index, 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 4% MSCI Emerging Markets Index, 3% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets) and 3% Barclays U.S. Aggregate Index (an index of fixed income securities). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Total returns (before taxes) (%)

Calendar Years ended December 31

Best quarter
(06/30/2009): 19.62

Worst quarter
(09/30/2011): (16.65)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 6.89

Average annual total returns (for periods ended December 31, 2012) (%)

Average Annual Total Returns Legg Mason Target Retirement 2045	1 year	Since inception	Inception date
Class C	13.97%	2.25%	Aug. 29, 2008
Class C Return after taxes on distributions	13.67%	1.91%	Aug. 29, 2008
Class C Return after taxes on distributions and sale of fund shares	9.08%	1.71%	Aug. 29, 2008
Class A	9.22%	1.61%	Aug. 29, 2008
Class FI	15.95%	3.01%	Aug. 29, 2008
Class R	15.56%	2.74%	Aug. 29, 2008
Class I	16.22%	3.29%	Aug. 29, 2008
Dow Jones Target 2045 Index (reflects no deduction for fees, expenses or taxes)	15.32%	5.01%
Target Retirement 2045 Composite Index (reflects no deduction for fees, expenses or taxes)	16.91%	4.51%

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[1] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[2] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[3] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

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Legg Mason Target Retirement 2050

Legg Mason Target Retirement 2050

Investment objectives

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

From the five years before until the five years after the fund’s target retirement date of 2050 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Fees and expenses of the fund

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder fees (paid directly from your investment)

Shareholder Fees Legg Mason Target Retirement 2050 (USD $)		Class A		Class C	Class FI	Class R	Class R1	Class I	Class IS
Maximum sales charge (load) imposed on purchases (as a % of offering price)		5.75%		none	none	none	none	none	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)		none	[1]	1.00%	none	none	none	none	none
Small account fee ($)	[2]	15		15	none	none	none	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Annual Fund Operating Expenses Legg Mason Target Retirement 2050		Class A	Class C	Class FI	Class R	Class R1	Class I	Class IS
Management fees		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and service (12b-1) fees		0.25%	1.00%	0.25%	0.50%	1.00%	none	none
Other expenses	[1]	5.80%	5.99%	5.42%	5.19%	5.19%	5.68%	5.59%
Acquired fund fees and expenses (fees and expenses of underlying funds)		0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%
Total annual fund operating expenses	[2]	6.74%	7.68%	6.36%	6.38%	6.88%	6.37%	6.28%
Fees waived and/or expenses reimbursed	[3]	(5.59%)	(5.78%)	(5.21%)	(4.98%)	(4.98%)	(5.52%)	(5.53%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses		1.15%	1.90%	1.15%	1.40%	1.90%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Number of years you own your shares ($)

Expense Example Legg Mason Target Retirement 2050 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,982	3,233	6,177
Class C	293	1,734	3,194	6,516
Class FI	117	1,420	2,688	5,710
Class R	143	1,446	2,714	5,734
Class R1	193	1,585	2,925	6,061
Class I	87	1,396	2,669	5,703
Class IS	77	1,369	2,629	5,640

Number of years you own your shares ($)

Expense Example, No Redemption Legg Mason Target Retirement 2050 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,982	3,233	6,177
Class C	193	1,734	3,194	6,516
Class FI	117	1,420	2,688	5,710
Class R	143	1,446	2,714	5,734
Class R1	193	1,585	2,925	6,061
Class I	87	1,396	2,669	5,703
Class IS	77	1,369	2,629	5,640

Portfolio turnover.

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Principal investment strategies

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2050. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2050, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds	Fixed Income Funds	Inflation-Hedging Funds
Target Retirement 2050	94%	6%	0%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2065, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2065. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Certain risks

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses to the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 51% Russell 1000 Index, 26% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 8% Russell 2000 Index, 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 4% MSCI Emerging Markets Index, 3% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets) and 3% Barclays U.S. Aggregate Index (an index of fixed income securities). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Total returns (before taxes) (%)

Calendar Years ended December 31

Best quarter
(06/30/2009): 19.73

Worst quarter
(09/30/2011): (16.50)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 6.85

Average annual total returns (for periods ended December 31, 2012) (%)

Average Annual Total Returns Legg Mason Target Retirement 2050	1 year	Since inception	Inception date
Class C	14.04%	2.35%	Aug. 29, 2008
Class C Return after taxes on distributions	13.76%	2.03%	Aug. 29, 2008
Class C Return after taxes on distributions and sale of fund shares	9.12%	1.80%	Aug. 29, 2008
Class A	9.22%	1.70%	Aug. 29, 2008
Class FI	15.83%	3.08%	Aug. 29, 2008
Class R	15.63%	2.84%	Aug. 29, 2008
Class I	16.27%	3.41%	Aug. 29, 2008
Dow Jones Target 2050 Index (reflects no deduction for fees, expenses or taxes)	15.35%	5.01%
Target Retirement 2050 Composite Index (reflects no deduction for fees, expenses or taxes)	16.91%	4.51%

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[1] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[2] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[3] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

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Legg Mason Target Retirement 2015

Legg Mason Target Retirement 2015

Investment objectives

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

The fund will seek to reduce volatility as a secondary objective until five years after the fund’s target retirement date of 2015 (the “Dynamic Rebalancing Period”).

Fees and expenses of the fund

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees Legg Mason Target Retirement 2015 (USD $)		Class A		Class C	Class FI	Class R	Class R1	Class I	Class IS
Maximum sales charge (load) imposed on purchases (as a % of offering price)		5.75%		none	none	none	none	none	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)		none	[1]	1.00%	none	none	none	none	none
Small account fee ($)	[2]	15		15	none	none	none	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Annual Fund Operating Expenses Legg Mason Target Retirement 2015		Class A	Class C	Class FI	Class R	Class R1	Class I	Class IS
Management fees		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and service (12b-1) fees		0.25%	1.00%	0.25%	0.50%	1.00%	none	none
Other expenses	[1]	4.27%	4.06%	3.61%	3.61%	3.61%	4.23%	3.89%
Acquired fund fees and expenses (fees and expenses of underlying funds)		0.57%	0.57%	0.57%	0.57%	0.57%	0.57%	0.57%
Total annual fund operating expenses	[2]	5.19%	5.73%	4.53%	4.78%	5.28%	4.90%	4.56%
Fees waived and/or expenses reimbursed	[3]	(4.04%)	(3.83%)	(3.38%)	(3.38%)	(3.38%)	(4.05%)	(3.81%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses		1.15%	1.90%	1.15%	1.40%	1.90%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Number of years you own your shares ($)

Expense Example Legg Mason Target Retirement 2015 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,700	2,711	5,221
Class C	293	1,366	2,522	5,338
Class FI	117	1,063	2,017	4,442
Class R	143	1,136	2,133	4,644
Class R1	193	1,279	2,359	5,033
Class I	87	1,109	2,133	4,702
Class IS	77	1,032	1,996	4,441

Number of years you own your shares ($)

Expense Example, No Redemption Legg Mason Target Retirement 2015 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,700	2,711	5,221
Class C	193	1,366	2,522	5,338
Class FI	117	1,063	2,017	4,442
Class R	143	1,136	2,133	4,644
Class R1	193	1,279	2,359	5,033
Class I	87	1,109	2,133	4,702
Class IS	77	1,032	1,996	4,441

Portfolio turnover.

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 202% of the average value of its portfolio.

Principal investment strategies

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income, inflation-hedging and short-term defensive instruments—and investment styles. The fund is designed for investors expecting to retire around 2015. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2015, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds			Fixed Income Funds			Inflation-Hedging Funds
Target Retirement 2015		53	%		42	%		5	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2030, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

The fund is currently in its Dynamic Rebalancing Period and, at times, may not follow the Target Allocation indicated by the glide path. LMGAA will revert to managing this fund according to the Target Allocation at the end of the Dynamic Rebalancing Period on December 31, 2019.

Dynamic risk management. The Dynamic Risk Management strategy seeks to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets. As of January 31, 2013, the fund had 0% of its net assets allocated to short-term defensive instruments.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”), based on a formula that takes into account the fund’s current NAV, macro-economic conditions and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy seeks to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. As of January 31, 2013, the fund had less than 1% of its net assets allocated to this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2030. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Certain risks

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 27% Barclays U.S. Aggregate Index (an index of fixed income securities), 22% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 19% Russell 1000 Index, 15% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index, 4% MSCI Emerging Markets Index and 3% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Total returns (before taxes) (%)

Calendar Years ended December 31

Best quarter
(06/30/2009): 18.05

Worst quarter
(09/30/2011): (10.63)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 3.00

Average annual total returns (for periods ended December 31, 2012) (%)

Average Annual Total Returns Legg Mason Target Retirement 2015	1 year	Since inception	Inception date
Class C	6.16%	2.28%	Aug. 29, 2008
Class C Return after taxes on distributions	5.85%	1.70%	Aug. 29, 2008
Class C Return after taxes on distributions and sale of fund shares	4.01%	1.60%	Aug. 29, 2008
Class A	1.77%	1.64%	Aug. 29, 2008
Class FI	7.98%	3.06%	Aug. 29, 2008
Class R	7.70%	2.79%	Aug. 29, 2008
Class I	8.22%	3.34%	Aug. 29, 2008
Dow Jones Target 2015 Index (reflects no deduction for fees, expenses or taxes)	7.65%	5.43%
Target Retirement 2015 Composite Index (reflects no deduction for fees, expenses or taxes)	12.19%	5.11%

The fund’s investment objectives and investment strategies were changed in August 2011 and its investment strategies were further revised in November 2011. The fund’s historical performance for the periods prior to August 1, 2011 and November 21, 2011 is based on the fund’s former investment objectives and strategies.

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[1] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[2] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[3] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

LEGG MASON PARTNERS EQUITY TRUST

Prospectus Date

rr_ProspectusDate

Jun. 01, 2013

Legg Mason Target Retirement 2050

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Legg Mason Target Retirement 2050

Objective [Heading]

rr_ObjectiveHeading

Investment objectives

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

From the five years before until the five years after the fund’s target retirement date of 2050 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses of the fund

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

December 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover.

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 39% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

39.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

25,000

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

“Other expenses” are estimated for the current fiscal year. Actual expenses may differ from estimates.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund’s shareholder reports, because the ratios in the financial highlights tables reflect the fund’s operating expenses and do not include acquired fund fees and expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

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This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

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Number of years you own your shares ($)

Expense Example, No Redemption, By Year, Caption [Text]

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Number of years you own your shares ($)

Strategy [Heading]

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Principal investment strategies

Strategy Narrative [Text Block]

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The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2050. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2050, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds	Fixed Income Funds	Inflation-Hedging Funds
Target Retirement 2050	94%	6%	0%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2065, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2065. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Risk [Heading]

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Certain risks

Risk Narrative [Text Block]

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Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses to the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Risk Lose Money [Text]

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You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.

Bar Chart and Performance Table [Heading]

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Performance

Performance Narrative [Text Block]

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The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 51% Russell 1000 Index, 26% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 8% Russell 2000 Index, 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 4% MSCI Emerging Markets Index, 3% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets) and 3% Barclays U.S. Aggregate Index (an index of fixed income securities). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Performance Information Illustrates Variability of Returns [Text]

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The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark.

Performance Availability Phone [Text]

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1-877-721-1926

Performance Availability Website Address [Text]

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http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class)

Performance Past Does Not Indicate Future [Text]

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The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Bar Chart [Heading]

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Total returns (before taxes) (%)

Bar Chart Does Not Reflect Sales Loads [Text]

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Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Bar Chart Closing [Text Block]

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Calendar Years ended December 31

Best quarter
(06/30/2009): 19.73

Worst quarter
(09/30/2011): (16.50)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 6.85

Performance Table Heading

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Average annual total returns (for periods ended December 31, 2012) (%)

Performance Table Uses Highest Federal Rate

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The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

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Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

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The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Performance Table Narrative

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The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Legg Mason Target Retirement 2050 | Class A

Risk/Return:

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Maximum sales charge (load) imposed on purchases (as a % of offering price)

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5.75%

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

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none

^[1]

Small account fee ($)

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15

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Management fees

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0.10%

Distribution and service (12b-1) fees

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0.25%

Other expenses

rr_OtherExpensesOverAssets

5.80%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

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0.59%

Total annual fund operating expenses

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6.74%

^[4]

Fees waived and/or expenses reimbursed

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(5.59%)

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Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

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685

3 years

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1,982

5 years

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3,233

10 years

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6,177

1 year

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685

3 years

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1,982

5 years

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3,233

10 years

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6,177

1 year

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9.22%

Since inception

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1.70%

Inception date

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Aug. 29, 2008

Legg Mason Target Retirement 2050 | Class C

Risk/Return:

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Maximum sales charge (load) imposed on purchases (as a % of offering price)

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none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

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1.00%

Small account fee ($)

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15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

5.99%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

7.68%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(5.78%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

293

3 years

rr_ExpenseExampleYear03

1,734

5 years

rr_ExpenseExampleYear05

3,194

10 years

rr_ExpenseExampleYear10

6,516

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,734

5 years

rr_ExpenseExampleNoRedemptionYear05

3,194

10 years

rr_ExpenseExampleNoRedemptionYear10

6,516

2009

rr_AnnualReturn2009

28.48%

2010

rr_AnnualReturn2010

13.80%

2011

rr_AnnualReturn2011

(4.31%)

2012

rr_AnnualReturn2012

15.04%

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date return as of the most recent calendar quarter

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

6.85%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

19.73%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(16.50%)

1 year

rr_AverageAnnualReturnYear01

14.04%

Since inception

rr_AverageAnnualReturnSinceInception

2.35%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2050 | Class FI

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

5.42%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.36%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(5.21%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

117

3 years

rr_ExpenseExampleYear03

1,420

5 years

rr_ExpenseExampleYear05

2,688

10 years

rr_ExpenseExampleYear10

5,710

1 year

rr_ExpenseExampleNoRedemptionYear01

117

3 years

rr_ExpenseExampleNoRedemptionYear03

1,420

5 years

rr_ExpenseExampleNoRedemptionYear05

2,688

10 years

rr_ExpenseExampleNoRedemptionYear10

5,710

1 year

rr_AverageAnnualReturnYear01

15.83%

Since inception

rr_AverageAnnualReturnSinceInception

3.08%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2050 | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

5.19%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.38%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(4.98%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.40%

1 year

rr_ExpenseExampleYear01

143

3 years

rr_ExpenseExampleYear03

1,446

5 years

rr_ExpenseExampleYear05

2,714

10 years

rr_ExpenseExampleYear10

5,734

1 year

rr_ExpenseExampleNoRedemptionYear01

143

3 years

rr_ExpenseExampleNoRedemptionYear03

1,446

5 years

rr_ExpenseExampleNoRedemptionYear05

2,714

10 years

rr_ExpenseExampleNoRedemptionYear10

5,734

1 year

rr_AverageAnnualReturnYear01

15.63%

Since inception

rr_AverageAnnualReturnSinceInception

2.84%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2050 | Class R1

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

5.19%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.88%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(4.98%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

193

3 years

rr_ExpenseExampleYear03

1,585

5 years

rr_ExpenseExampleYear05

2,925

10 years

rr_ExpenseExampleYear10

6,061

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,585

5 years

rr_ExpenseExampleNoRedemptionYear05

2,925

10 years

rr_ExpenseExampleNoRedemptionYear10

6,061

Legg Mason Target Retirement 2050 | Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

5.68%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.37%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(5.52%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.85%

1 year

rr_ExpenseExampleYear01

87

3 years

rr_ExpenseExampleYear03

1,396

5 years

rr_ExpenseExampleYear05

2,669

10 years

rr_ExpenseExampleYear10

5,703

1 year

rr_ExpenseExampleNoRedemptionYear01

87

3 years

rr_ExpenseExampleNoRedemptionYear03

1,396

5 years

rr_ExpenseExampleNoRedemptionYear05

2,669

10 years

rr_ExpenseExampleNoRedemptionYear10

5,703

1 year

rr_AverageAnnualReturnYear01

16.27%

Since inception

rr_AverageAnnualReturnSinceInception

3.41%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2050 | Class IS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

5.59%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

6.28%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(5.53%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.75%

1 year

rr_ExpenseExampleYear01

77

3 years

rr_ExpenseExampleYear03

1,369

5 years

rr_ExpenseExampleYear05

2,629

10 years

rr_ExpenseExampleYear10

5,640

1 year

rr_ExpenseExampleNoRedemptionYear01

77

3 years

rr_ExpenseExampleNoRedemptionYear03

1,369

5 years

rr_ExpenseExampleNoRedemptionYear05

2,629

10 years

rr_ExpenseExampleNoRedemptionYear10

5,640

Legg Mason Target Retirement 2050 | Return after taxes on distributions | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

13.76%

Since inception

rr_AverageAnnualReturnSinceInception

2.03%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2050 | Return after taxes on distributions and sale of fund shares | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

9.12%

Since inception

rr_AverageAnnualReturnSinceInception

1.80%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2050 | Dow Jones Target 2050 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

15.35%

Since inception

rr_AverageAnnualReturnSinceInception

5.01%

Legg Mason Target Retirement 2050 | Target Retirement 2050 Composite Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

16.91%

Since inception

rr_AverageAnnualReturnSinceInception

4.51%

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[3] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[4] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[5] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

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Legg Mason Target Retirement 2040

Legg Mason Target Retirement 2040

Investment objectives

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

From the five years before until five years after the fund’s target retirement date of 2040 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Fees and expenses of the fund

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees Legg Mason Target Retirement 2040 (USD $)		Class A		Class C	Class FI	Class R	Class R1	Class I	Class IS
Maximum sales charge (load) imposed on purchases (as a % of offering price)		5.75%		none	none	none	none	none	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)		none	[1]	1.00%	none	none	none	none	none
Small account fee ($)	[2]	15		15	none	none	none	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Annual Fund Operating Expenses Legg Mason Target Retirement 2040		Class A	Class C	Class FI	Class R	Class R1	Class I	Class IS
Management fees		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and service (12b-1) fees		0.25%	1.00%	0.25%	0.50%	1.00%	none	none
Other expenses	[1]	3.88%	3.65%	3.10%	3.06%	3.06%	3.41%	3.29%
Acquired fund fees and expenses (fees and expenses of underlying funds)		0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%
Total annual fund operating expenses	[2]	4.82%	5.34%	4.04%	4.25%	4.75%	4.10%	3.98%
Fees waived and/or expenses reimbursed	[3]	(3.67%)	(3.44%)	(2.89%)	(2.85%)	(2.85%)	(3.25%)	(3.23%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses		1.15%	1.90%	1.15%	1.40%	1.90%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Number of years you own your shares ($)

Expense Example Legg Mason Target Retirement 2040 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,630	2,579	4,965
Class C	293	1,291	2,381	5,074
Class FI	117	965	1,829	4,061
Class R	143	1,030	1,931	4,242
Class R1	193	1,175	2,162	4,650
Class I	87	949	1,827	4,092
Class IS	77	915	1,771	3,987

Number of years you own your shares ($)

Expense Example, No Redemption Legg Mason Target Retirement 2040 (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,630	2,579	4,965
Class C	193	1,291	2,381	5,074
Class FI	117	965	1,829	4,061
Class R	143	1,030	1,931	4,242
Class R1	193	1,175	2,162	4,650
Class I	87	949	1,827	4,092
Class IS	77	915	1,771	3,987

Portfolio turnover.

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 48% of the average value of its portfolio.

Principal investment strategies

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2040. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2040, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds	Fixed Income Funds	Inflation-Hedging Funds
Target Retirement 2040	92%	8%	0%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:





During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2055, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Dynamic Risk Management attempts to limit losses by allocating fund assets away from equity and long-term fixed income funds. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2055. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Certain risks

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 52% Russell 1000 Index, 28% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets), 5% Russell 2000 Index, 3% Barclays U.S. Aggregate Index (an index of fixed income securities) and 2% MSCI Emerging Markets Index. Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Total returns (before taxes) (%)

Calendar Years ended December 31

Best quarter
(06/30/2009): 19.66

Worst quarter
(09/30/2011): (16.03)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 7.01

Average annual total returns (for periods ended December 31, 2012) (%)

Average Annual Total Returns Legg Mason Target Retirement 2040	1 year	Since inception	Inception date
Class C	13.78%	2.39%	Aug. 29, 2008
Class C Return after taxes on distributions	13.44%	2.05%	Aug. 29, 2008
Class C Return after taxes on distributions and sale of fund shares	8.95%	1.83%	Aug. 29, 2008
Class A	9.09%	1.75%	Aug. 29, 2008
Class FI	15.74%	3.17%	Aug. 29, 2008
Class R	15.47%	2.90%	Aug. 29, 2008
Class I	16.01%	3.45%	Aug. 29, 2008
Dow Jones Target 2040 Index (reflects no deduction for fees, expenses or taxes)	14.88%	4.95%
Target Retirement 2040 Composite Index (reflects no deduction for fees, expenses or taxes)	16.93%	4.57%

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[1] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[2] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[3] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	LEGG MASON PARTNERS EQUITY TRUST
Prospectus Date	rr_ProspectusDate	Jun. 01, 2013
Document Creation Date	dei_DocumentCreationDate	May 21, 2013

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Registrant Name

dei_EntityRegistrantName

LEGG MASON PARTNERS EQUITY TRUST

Prospectus Date

rr_ProspectusDate

Jun. 01, 2013

Legg Mason Target Retirement 2030

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Legg Mason Target Retirement 2030

Objective [Heading]

rr_ObjectiveHeading

Investment objectives

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Objective, Secondary [Text Block]

rr_ObjectiveSecondaryTextBlock

From the five years before until the five years after the fund’s target retirement date of 2030 (the “Dynamic Rebalancing Period”), the fund will seek to reduce volatility as a secondary objective.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses of the fund

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

December 31, 2014

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover.

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 49% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

49.00%

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

25,000

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

“Other expenses” are estimated for the current fiscal year. Actual expenses may differ from estimates.

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund’s shareholder reports, because the ratios in the financial highlights tables reflect the fund’s operating expenses and do not include acquired fund fees and expenses.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Number of years you own your shares ($)

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

Number of years you own your shares ($)

Strategy [Heading]

rr_StrategyHeading

Principal investment strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objectives by investing in a combination of underlying funds representing a variety of broad asset classes—equity, fixed income and inflation-hedging—and investment styles. The fund is designed for investors expecting to retire around 2030. The fund’s asset mix has been designed on the expectation that investors will begin to withdraw assets from the fund during 2030, but will continue to maintain a significant portion of their investment in the fund for a period of time—perhaps 10 to 20 years—following that date. While the fund seeks to reduce volatility during the Dynamic Rebalancing Period, the fund may not achieve its goals. You should take these factors into consideration when deciding on an investment in the fund.

The fund generally seeks to maintain a certain Target Allocation, as described below. However, during the Dynamic Rebalancing Period, Legg Mason Global Asset Allocation, LLC (“LMGAA”), one of the fund’s subadvisers, in its discretion, may adjust the fund’s asset mix as often as daily and may vary the fund’s allocation substantially from the Target Allocation. The fund’s Target Allocation for equity funds (including real estate-related funds), fixed income funds and inflation-hedging funds is shown in the table below:

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement 2030	73	%	27	%	0	%

LMGAA is responsible for implementation of the fund’s overall asset allocation. During the fund’s Dynamic Rebalancing Period, LMGAA also manages the assets allocated to the Dynamic Risk Management strategy. Western Asset Management Company (“Western Asset”), the fund’s other subadviser, manages the assets allocated to the Event Risk Management strategy, described below, during the fund’s Dynamic Rebalancing Period.

Glide path period
Over time, the allocation to asset classes and underlying funds will change according to a predetermined “glide path.” The glide path represents the shifting of asset classes over time. The glide path is detailed in the chart below:



During the time that the fund’s asset allocations track the glide path, the fund’s asset mix will gradually become more conservative until approximately 2045, or 15 years after the target date, at which time the asset mix will become static. This reflects the goal of pursuing the highest total return, consistent with a reasonable amount of risk, during the investor’s pre-retirement and early retirement years. By following these investment strategies after the fund reaches its target date, the fund seeks to reduce the likelihood that an investor will experience a significant loss of capital at a more advanced age.

The Target Allocations reflected in the glide path are “neutral” allocations, which do not reflect tactical decisions made by LMGAA to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Dynamic rebalancing period
During the Dynamic Rebalancing Period, the fund will not be managed strictly according to the standard Target Allocation. Instead, LMGAA will implement a combination of risk management strategies that will attempt to limit downside volatility within the fund. These strategies include Dynamic Risk Management and Event Risk Management, as described below. Through both strategies, the fund gives up some of the potential for high total return that could be achieved if the fund were to follow its Target Allocation under positive market conditions. In exchange, these strategies are intended to result in less significant declines in the fund’s net asset value (“NAV”) under negative market conditions. The fund’s NAV will fluctuate and is not guaranteed.

Dynamic risk management. The Dynamic Risk Management strategy will seek to reduce the fund’s market risk exposure and volatility. As frequently as daily, the Dynamic Risk Management strategy may increase the fund’s exposure to short-term defensive instruments (including Treasury bills, money market funds and cash) in response to certain levels of negative fund performance. At other times Dynamic Risk Management may decrease the fund’s exposure to short-term defensive instruments and increase its exposure to equity funds and long-term fixed income funds in order to return to the fund’s Target Allocation in response to certain levels of positive fund performance. The maximum daily allocation to short-term defensive instruments will be 95% of the fund’s net assets.

In response to certain levels of negative fund performance, LMGAA may increase the fund’s exposure to short-term defensive instruments (“de-risking”) based on a formula that takes into account the fund’s current NAV, macro-economic conditions, and the fund’s underlying volatility. In order to implement this strategy, LMGAA anticipates that it will initially attempt to sell shares of ETFs and other liquid securities or engage in short sale transactions involving futures. Then, LMGAA would redeem underlying open-end mutual fund shares as needed. In response to certain levels of positive fund performance, the fund may purchase ETFs or underlying open-end mutual fund shares or cover short futures positions (when the fund is not managed strictly according to the standard Target Allocation). LMGAA, in its discretion, will determine the levels and timing for Dynamic Risk Management. If LMGAA determines that de-risking is no longer appropriate, the fund will reverse this process, sell short-term defensive instruments and purchase equity funds and long-term fixed income funds in accordance with the fund’s Target Allocation.

LMGAA may from time to time make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets. When varying exposures among underlying funds, LMGAA will examine relative values and prospects among the underlying funds’ asset classes, as well as the capacity of the underlying funds to absorb additional cash flow.

Event risk management. The Event Risk Management strategy will seek to reduce the impact to the fund of market declines during a short period of time caused by, for example, sudden and substantial movements in the equity markets, interest rates or credit spreads. The fund initially will invest up to 2% of its net assets in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). However, the fund may invest up to 7% of its net assets at the time of purchase in this strategy (as measured by the premiums paid on options or initial margin on futures contracts). If the fund’s holdings in this strategy increase in value to over 7% of its net assets as a result of market movements, the fund will reduce, at least monthly, the amount of its assets invested in this strategy to no more than 7% of its net assets. The value of the fund’s assets invested in this strategy may be substantially higher than the value of the premiums paid or initial margin amounts on the instruments used to implement the strategy. If the value of the instruments in the Event Risk Management strategy declines after the fund has engaged in “de-risking,” the fund’s NAV could decline even if the broader markets rise in value. Conversely, if the value of the instruments in the Event Risk Management strategy increases after the fund has engaged in “de-risking,” the fund’s net asset value could increase even if the broader markets fall in value.

Western Asset’s views and outlook regarding potential unexpected market movements will determine the investments and strategies it employs in implementing the Event Risk Management strategy. During normal market conditions, the fund will implement the Event Risk Management strategy through investments in options, futures, swaps or other instruments. Since the Event Risk Management strategy seeks to primarily benefit from large and unexpected market movements, there may be times when the investment and transaction costs related to hedging will result in losses to the fund. The Event Risk Management strategy will be actively managed in an effort to reduce these costs when possible.

Static allocation period
The fund’s Target Allocation will become static 15 years after the target date. At this time, when the fund’s Target Allocation will match the Target Allocation of Legg Mason Target Retirement Fund (the “Retirement Fund”), the fund’s Board of Trustees may combine the fund with the Retirement Fund without shareholder approval, and the fund’s shareholders will become shareholders of the Retirement Fund. This is expected to occur approximately in the year 2045. This combination is expected to be tax-free under current law. Shareholders will be provided with additional information at that time.

The Retirement Fund’s Target Allocation is 33% in equity, 62% in fixed income and 5% in inflation-hedging funds.

Risk [Heading]

rr_RiskHeading

Certain risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objectives. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. In addition, you may experience losses near, at or after the target date. You should not rely solely on the target date when choosing to invest in the fund or deciding to remain invested in the fund. You should consider the fund’s investment strategies over the whole life of the fund. Unlike many other target retirement date funds, the fund, during the Dynamic Rebalancing Period, may not follow the Target Allocation indicated by the glide path. There is no assurance that the fund will provide sufficient retirement income at and after the target date. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of certain underlying funds and is affiliated with the manager of other underlying funds. In addition, the fund may invest in certain underlying funds for which LMGAA or Western Asset serve as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager, LMGAA or Western Asset fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets or to maintain the fund’s allocation to those funds for which the fees paid to the manager or a subadviser are higher than the fees paid by other underlying funds or to those funds for which a subadviser serves as adviser. However, the fund has adopted procedures to mitigate these concerns.

In order to implement the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts.

Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, there may be conflicts of interest if unaffiliated ETFs are sold before affiliated underlying open-end mutual funds.

Allocation risk. The fund’s ability to achieve its investment objectives depends upon LMGAA’s skill in determining the fund’s asset class allocation, creating and applying formulas for de-risking or ending de-risking, determining when to engage in Event Risk Management and in selecting the best mix of underlying funds. The value of your investment may decrease if LMGAA’s judgment about the attractiveness, value or market trends affecting a particular asset class, investment style, technique or strategy, underlying fund or other issuer is incorrect.

In implementing the Dynamic Risk Management or Event Risk Management strategies, the fund will be subject to heightened allocation risk, as LMGAA will have discretion in determining the fund’s asset class allocation. If the fund increases its exposure to short-term defensive instruments at inopportune times or for extended periods of time, the fund may experience lower performance and greater losses.

Cash management and defensive investing risk. During the Dynamic Rebalancing Period, the fund may have significant exposure to short-term defensive instruments, which typically will include Treasury bills, money market funds and cash. The fund may also engage in short sale transactions involving index options and index futures contracts. The value of these investments held by the fund can fluctuate. Like other fixed income securities, they are subject to risk, including market, interest rate and credit risk. If the fund holds cash uninvested, it will be subject to the credit risk of the depository institution holding the cash. If the fund holds cash uninvested, the fund will not earn income on the cash. If the fund has a significant amount of exposure to short-term defensive instruments or the fund sells index options or index futures contracts short, it may not achieve high total returns.

Derivatives risk. Using derivatives may have a leveraging effect, which may result in a disproportionate increase in fund losses on the investment, and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives also can increase fund volatility. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation are not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance. Derivatives used for hedging purposes may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Dynamic risk management strategy risk. In implementing the Dynamic Risk Management strategy, LMGAA anticipates that it will initially sell shares the fund holds in ETFs and other liquid securities or engage in short sale transactions involving index options and index futures contracts. Then, LMGAA would redeem shares of underlying open-end mutual funds as needed. As a result, the fund’s assets may be more concentrated in its underlying mutual fund holdings. In addition, during periods of market volatility, the share prices of ETFs may deviate significantly from their NAVs. Therefore, selling shares of ETFs during periods of market volatility may result in greater losses than redeeming open-end mutual fund holdings. Similarly, the use of derivatives may cause the fund to experience greater losses than redeeming mutual fund holdings. The fund may incur additional trading costs while implementing the Dynamic Risk Management strategy, which may reduce the fund’s performance. There is no guarantee that the Dynamic Risk Management strategy will work and shareholders should evaluate their ability to invest for the long-term, especially during periods of downturn in the market.

Event risk management strategy risk. The Event Risk Management strategy may involve entering into transactions involving options, futures and swaps that are expected to increase in value during the occurrence of certain market events. An instrument used to hedge market event risk could lose all or a portion of its value even in a period of severe market stress. Implementation of the strategy may result in the fund holding options and futures positions that take contradictory views on market movements. The costs of purchasing and selling these instruments may reduce the fund’s return. The fund may not be able to close out a position at the desired time or price. There is no guarantee that the Event Risk Management strategy will work and shareholders should evaluate their ability to invest for the long term, especially during periods of downturn in the market.

Tax risk. The fund’s hedging strategy may result in the fund deferring, possibly indefinitely, certain of its realized losses for U.S. federal income tax purposes, potentially increasing the amount of the fund’s taxable distributions paid to shareholders.

Short sales risk. A short sale of a security involves the risk that instead of declining, the price of the security sold short will rise. If the price of the security sold short increases between the time of the short sale and the time the fund replaces the borrowed security, the fund will realize a loss. The short sale of securities involves the possibility of a theoretically unlimited loss since there is a theoretically unlimited potential for the market price of the security sold short to increase. Shorting futures may have an imperfect correlation to the assets held by the fund and may not adequately protect against losses in or may result in greater losses for the fund’s portfolio.

Segregated assets risk. In connection with certain transactions that may give rise to future payment obligations, including many types of derivatives, the fund may be required to maintain a segregated amount of cash or liquid securities to cover the position. Segregated securities cannot be sold while the position they are covering is outstanding, unless they are replaced with other securities of equal value. As a result, there is the possibility that segregation of a large percentage of the fund’s assets, in some circumstances, may limit the subadvisers’ flexibility.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income, inflation-hedging investments and short-term defensive instruments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s adviser believes appropriate and may offer greater potential for losses.

Liquidity risk. Some assets or derivatives held by the fund or an underlying fund or futures sold by the fund or an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets or derivatives may also be difficult to value. If the fund or an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund or an underlying fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to NAV. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile. In addition, after the fund reaches the target date, it is expected that the assets will decline as investors begin to withdraw their assets from the fund, causing gross expenses to increase.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 33% Russell 1000 Index, 27% Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East Index, 12% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 11% Barclays U.S. Aggregate Index (an index of fixed income securities), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index, 3% JPMorgan Emerging Markets Bond Index Plus (a total return index that tracks the traded market for U.S. dollar denominated Brady and other similar sovereign restructured bonds traded in emerging markets), 3% MSCI Emerging Markets Index and 1% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index). Over time, the composite benchmark will change with the fund’s asset allocation; and the composite benchmark allocation will gradually become more conservative. When the fund’s composite benchmark changes, the composite’s new allocation is utilized to calculate composite performance from and after such changes. Composite performance for periods prior to the change is not recalculated or restated based on the composite’s new allocation but rather reflects the composite benchmark’s actual allocation during that period, which may be different than the current composite benchmark allocation.

The fund makes updated performance information available at the fund’s website, http:/www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark.

Performance Availability Phone [Text]

rr_PerformanceAvailabilityPhone

1-877-721-1926

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

http:/www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class)

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Bar Chart [Heading]

rr_BarChartHeading

Total returns (before taxes) (%)

Bar Chart Does Not Reflect Sales Loads [Text]

rr_BarChartDoesNotReflectSalesLoads

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Calendar Years ended December 31

Best quarter
(06/30/2009): 18.46

Worst quarter
(09/30/2011): (14.19)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 5.11

Performance Table Heading

rr_PerformanceTableHeading

Average annual total returns (for periods ended December 31, 2012) (%)

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.

Performance Table Not Relevant to Tax Deferred

rr_PerformanceTableNotRelevantToTaxDeferred

Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Performance Table One Class of after Tax Shown [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Performance Table Narrative

rr_PerformanceTableNarrativeTextBlock

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

Legg Mason Target Retirement 2030 | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.75%

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.88%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.82%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.67%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

685

3 years

rr_ExpenseExampleYear03

1,630

5 years

rr_ExpenseExampleYear05

2,579

10 years

rr_ExpenseExampleYear10

4,965

1 year

rr_ExpenseExampleNoRedemptionYear01

685

3 years

rr_ExpenseExampleNoRedemptionYear03

1,630

5 years

rr_ExpenseExampleNoRedemptionYear05

2,579

10 years

rr_ExpenseExampleNoRedemptionYear10

4,965

1 year

rr_AverageAnnualReturnYear01

8.75%

Since inception

rr_AverageAnnualReturnSinceInception

2.32%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2030 | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

1.00%

Small account fee ($)

rr_MaximumAccountFee

15

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.50%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

5.19%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.29%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

293

3 years

rr_ExpenseExampleYear03

1,262

5 years

rr_ExpenseExampleYear05

2,327

10 years

rr_ExpenseExampleYear10

4,972

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,262

5 years

rr_ExpenseExampleNoRedemptionYear05

2,327

10 years

rr_ExpenseExampleNoRedemptionYear10

4,972

2009

rr_AnnualReturn2009

26.60%

2010

rr_AnnualReturn2010

13.29%

2011

rr_AnnualReturn2011

(3.24%)

2012

rr_AnnualReturn2012

14.47%

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date return as of the most recent calendar quarter

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

5.11%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best quarter

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2009

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

18.46%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst quarter

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(14.19%)

1 year

rr_AverageAnnualReturnYear01

13.47%

Since inception

rr_AverageAnnualReturnSinceInception

2.96%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2030 | Class FI

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

3.00%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.94%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(2.79%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.15%

1 year

rr_ExpenseExampleYear01

117

3 years

rr_ExpenseExampleYear03

944

5 years

rr_ExpenseExampleYear05

1,789

10 years

rr_ExpenseExampleYear10

3,981

1 year

rr_ExpenseExampleNoRedemptionYear01

117

3 years

rr_ExpenseExampleNoRedemptionYear03

944

5 years

rr_ExpenseExampleNoRedemptionYear05

1,789

10 years

rr_ExpenseExampleNoRedemptionYear10

3,981

1 year

rr_AverageAnnualReturnYear01

15.34%

Since inception

rr_AverageAnnualReturnSinceInception

3.73%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2030 | Class R

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Other expenses

rr_OtherExpensesOverAssets

3.26%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.45%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.05%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.40%

1 year

rr_ExpenseExampleYear01

143

3 years

rr_ExpenseExampleYear03

1,070

5 years

rr_ExpenseExampleYear05

2,007

10 years

rr_ExpenseExampleYear10

4,396

1 year

rr_ExpenseExampleNoRedemptionYear01

143

3 years

rr_ExpenseExampleNoRedemptionYear03

1,070

5 years

rr_ExpenseExampleNoRedemptionYear05

2,007

10 years

rr_ExpenseExampleNoRedemptionYear10

4,396

1 year

rr_AverageAnnualReturnYear01

15.05%

Since inception

rr_AverageAnnualReturnSinceInception

3.47%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2030 | Class R1

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

3.26%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.95%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.05%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

1.90%

1 year

rr_ExpenseExampleYear01

193

3 years

rr_ExpenseExampleYear03

1,214

5 years

rr_ExpenseExampleYear05

2,236

10 years

rr_ExpenseExampleYear10

4,796

1 year

rr_ExpenseExampleNoRedemptionYear01

193

3 years

rr_ExpenseExampleNoRedemptionYear03

1,214

5 years

rr_ExpenseExampleNoRedemptionYear05

2,236

10 years

rr_ExpenseExampleNoRedemptionYear10

4,796

Legg Mason Target Retirement 2030 | Class I

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.32%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

4.01%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.16%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.85%

1 year

rr_ExpenseExampleYear01

87

3 years

rr_ExpenseExampleYear03

931

5 years

rr_ExpenseExampleYear05

1,791

10 years

rr_ExpenseExampleYear10

4,018

1 year

rr_ExpenseExampleNoRedemptionYear01

87

3 years

rr_ExpenseExampleNoRedemptionYear03

931

5 years

rr_ExpenseExampleNoRedemptionYear05

1,791

10 years

rr_ExpenseExampleNoRedemptionYear10

4,018

1 year

rr_AverageAnnualReturnYear01

15.69%

Since inception

rr_AverageAnnualReturnSinceInception

4.04%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2030 | Class IS

Risk/Return:

rr_RiskReturnAbstract

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)

rr_MaximumDeferredSalesChargeOverOther

none

Small account fee ($)

rr_MaximumAccountFee

none

^[2]

Management fees

rr_ManagementFeesOverAssets

0.10%

Distribution and service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

3.19%

^[3]

Acquired fund fees and expenses (fees and expenses of underlying funds)

rr_AcquiredFundFeesAndExpensesOverAssets

0.59%

Total annual fund operating expenses

rr_ExpensesOverAssets

3.88%

^[4]

Fees waived and/or expenses reimbursed

rr_FeeWaiverOrReimbursementOverAssets

(3.13%)

^[5]

Total annual fund operating expenses after waiving fees and/or reimbursing expenses

rr_NetExpensesOverAssets

0.75%

1 year

rr_ExpenseExampleYear01

77

3 years

rr_ExpenseExampleYear03

895

5 years

rr_ExpenseExampleYear05

1,732

10 years

rr_ExpenseExampleYear10

3,907

1 year

rr_ExpenseExampleNoRedemptionYear01

77

3 years

rr_ExpenseExampleNoRedemptionYear03

895

5 years

rr_ExpenseExampleNoRedemptionYear05

1,732

10 years

rr_ExpenseExampleNoRedemptionYear10

3,907

Legg Mason Target Retirement 2030 | Return after taxes on distributions | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

13.01%

Since inception

rr_AverageAnnualReturnSinceInception

2.43%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2030 | Return after taxes on distributions and sale of fund shares | Class C

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

8.76%

Since inception

rr_AverageAnnualReturnSinceInception

2.20%

Inception date

rr_AverageAnnualReturnInceptionDate

Aug. 29, 2008

Legg Mason Target Retirement 2030 | Dow Jones Target 2030 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

12.56%

Since inception

rr_AverageAnnualReturnSinceInception

5.07%

Legg Mason Target Retirement 2030 | Target Retirement 2030 Composite Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

1 year

rr_AverageAnnualReturnYear01

14.77%

Since inception

rr_AverageAnnualReturnSinceInception

4.44%

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[3] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[4] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[5] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Legg Mason Target Retirement Fund

Legg Mason Target Retirement Fund

Investment objective

The fund seeks the highest total return (that is, a combination of income and long-term capital appreciation) over time consistent with its asset mix.

Fees and expenses of the fund

The accompanying table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in funds sold by Legg Mason Investor Services, LLC (“LMIS”), the fund’s distributor. More information about these and other discounts is available from your financial intermediary, in this Prospectus on page 126 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 89 under the heading “Sales Charge Waivers and Reductions.”

The fund no longer offers Class R1 shares for purchase by new or existing investors.

Shareholder fees (paid directly from your investment)

Shareholder Fees Legg Mason Target Retirement Fund (USD $)		Class A		Class C	Class FI	Class R	Class R1	Class I	Class IS
Maximum sales charge (load) imposed on purchases (as a % of offering price)		5.75%		none	none	none	none	none	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption) (may be reduced over time)		none	[1]	1.00%	none	none	none	none	none
Small account fee ($)	[2]	15		15	none	none	none	none	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of
your investment) (%)

Annual Fund Operating Expenses Legg Mason Target Retirement Fund		Class A	Class C	Class FI	Class R	Class R1	Class I	Class IS
Management fees		0.10%	0.10%	0.10%	0.10%	0.10%	0.10%	0.10%
Distribution and service (12b-1) fees		0.25%	1.00%	0.25%	0.50%	1.00%	none	none
Other expenses	[1]	3.97%	4.01%	3.63%	3.27%	3.27%	3.55%	3.55%
Acquired fund fees and expenses (fees and expenses of underlying funds)		0.55%	0.55%	0.55%	0.55%	0.55%	0.55%	0.55%
Total annual fund operating expenses	[2]	4.87%	5.66%	4.53%	4.42%	4.92%	4.20%	4.20%
Fees waived and/or expenses reimbursed	[3]	(3.72%)	(3.76%)	(3.38%)	(3.02%)	(3.02%)	(3.35%)	(3.45%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses		1.15%	1.90%	1.15%	1.40%	1.90%	0.85%	0.75%

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The example assumes:

• You invest $10,000 in the fund for the time periods indicated
• Your investment has a 5% return each year and the fund’s operating expenses remain the same
• You reinvest all distributions and dividends without a sales charge

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Number of years you own your shares ($)

Expense Example Legg Mason Target Retirement Fund (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,640	2,597	5,000
Class C	293	1,353	2,497	5,292
Class FI	117	1,063	2,017	4,442
Class R	143	1,064	1,996	4,373
Class R1	193	1,208	2,225	4,774
Class I	87	969	1,865	4,168
Class IS	77	960	1,857	4,163

Number of years you own your shares ($)

Expense Example, No Redemption Legg Mason Target Retirement Fund (USD $)	1 year	3 years	5 years	10 years
Class A	685	1,640	2,597	5,000
Class C	193	1,353	2,497	5,292
Class FI	117	1,063	2,017	4,442
Class R	143	1,064	1,996	4,373
Class R1	193	1,208	2,225	4,774
Class I	87	969	1,865	4,168
Class IS	77	960	1,857	4,163

Portfolio turnover.

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the most recent fiscal year, the fund’s portfolio turnover rate was 47% of the average value of its portfolio.

Principal investment strategies

The fund is a fund of funds—it invests primarily in other funds. These underlying funds are open-end funds managed by the manager or its affiliates, or exchange-traded funds (“ETFs”) that are based on an index and managed by unaffiliated investment advisers.

The fund seeks to achieve its objective by investing in a combination of underlying funds representing a variety of broad asset classes—equity (including real estate-related funds), fixed income and inflation-hedging—and investment styles.

The fund maintains a static Target Allocation. The following table details the Target Allocation of the fund among broad asset classes.

	Asset Class
	Equity Funds		Fixed Income Funds		Inflation-Hedging Funds
Target Retirement Fund	33	%	62	%	5	%

The Target Allocation is a “neutral” allocation, which does not reflect tactical decisions made by Legg Mason Global Asset Allocation, LLC (“LMGAA”), the subadviser, to overweight or underweight a particular asset class. From time to time, LMGAA may make tactical increases or decreases to the fund’s investment in a particular asset class beyond the Target Allocation, based on a broad range of market and economic trends and quantitative factors. LMGAA may also allow the relative weightings of the fund’s investments in asset classes to vary from its Target Allocation in response to the markets.

Ordinarily, the fund’s investment in equity, fixed income or inflation-hedging funds is not expected to vary from the Target Allocation for that asset class by more than plus/minus 10%. Beyond that range, LMGAA will generally rebalance the fund.

Certain risks

Risk is inherent in all investing. There is no assurance that the fund will meet its investment objective. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the fund.

Affiliated funds risk. The fund’s manager serves as manager of the underlying Legg Mason and Western Asset funds and is affiliated with the manager of the underlying Royce funds. In addition, the fund may invest in certain underlying funds for which LMGAA serves as adviser. It is possible that a conflict of interest among the fund and the underlying funds could affect how the fund’s manager and LMGAA fulfill their fiduciary duties to the fund and the underlying funds. For example, LMGAA may have an incentive to allocate the fund’s assets to those funds for which the fees paid to the manager or LMGAA are higher than the fees paid by other underlying funds or to those funds for which LMGAA serves as adviser. However, the fund’s Board of Trustees believes the fund has been structured to mitigate these concerns.

Allocation risk. The fund’s ability to achieve its investment objective depends upon the subadvisers’ skill in determining the fund’s asset class allocation and in selecting the best mix of underlying funds. The value of your investment may decrease if the subadvisers’ judgment about the attractiveness, value or market trends affecting a particular asset class, investment style or technique, underlying fund or other issuer is incorrect.

Asset class variation risk. The underlying funds invest principally in the securities constituting their asset class (i.e., equity, fixed income or inflation-hedging investments). However, under normal market conditions, an underlying fund may vary the percentage of its assets in these securities (subject to any applicable regulatory requirements). Depending upon the percentage of securities in a particular asset class held by the underlying funds at any given time and the percentage of the fund’s assets invested in various underlying funds, the fund’s actual exposure to the securities in a particular asset class may vary substantially from its Target Allocation for that asset class.

Fund of funds risk. Your cost of investing in the fund, as a fund of funds, may be higher than the cost of investing in a mutual fund that only invests directly in individual securities. An underlying fund may change its investment objective or policies without the fund’s approval, which could force the fund to withdraw its investment from such underlying fund at a time that is unfavorable to the fund. In addition, one underlying fund may buy the same securities that another underlying fund sells. Therefore, the fund would indirectly bear the costs of these trades without accomplishing any investment purpose.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the fund’s or underlying fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions. If the market prices of the securities owned by the fund or underlying fund fall, the value of your investment in the fund will decline. The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. These market conditions may continue, worsen or spread, including in the United States, Europe and beyond. The withdrawal of this support, failure of efforts to respond to the crisis, or investor perception that such efforts are not succeeding could also negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund or underlying fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s or underlying fund’s investments may be negatively affected by the conditions in the countries experiencing the difficulties. In addition, policy and legislative changes in the United States and in other countries are changing many aspects of financial regulation. The impact of these changes on the markets, and the practical implications for market participants, may not be fully known for some time.

Fixed income securities risk. Fixed income securities are subject to a number of risks, including credit, market and interest rate risks. Credit risk is the risk that the issuer or obligor will not make timely payments of principal and interest. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of an underlying fund’s investment in that issuer. Market risk is the risk that the fixed income markets may become volatile and less liquid, and the market value of an investment may move up or down, sometimes quickly or unpredictably. Interest rate risk is the risk that the value of a fixed income security will fall when interest rates rise. In general, the longer the maturity and the lower the credit quality of a fixed income security, the more likely its value will decline.

Issuer risk. The value of a stock can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. An underlying fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small and medium capitalization companies have generally gone up or down more than those of large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Large capitalization company risk. Large capitalization companies may fall out of favor with investors.

Small and medium capitalization company risk. An underlying fund will be exposed to additional risks as a result of its investments in the securities of small and medium capitalization companies. Small and medium capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small and medium capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small and medium capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices an underlying fund’s portfolio managers believe appropriate and may offer greater potential for losses.

Liquidity risk. Some assets held by an underlying fund may be difficult to sell, or illiquid, particularly during times of market turmoil. Illiquid assets may also be difficult to value. If an underlying fund is forced to sell an illiquid asset to meet redemption requests or other cash needs, the fund may be forced to sell at a loss.

Growth and value investing risk. Growth or value securities as a group may be out of favor and underperform the overall equity market while the market concentrates on other types of securities. Growth securities typically are very sensitive to market movements because their market prices tend to reflect future expectations. When it appears those expectations will not be met, the prices of growth securities typically fall. The value approach to investing involves the risk that stocks may remain undervalued. An underlying fund may, like many growth or value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries and, indirectly, the fund’s exposure to those factors.

Foreign investment risk. The fund or an underlying fund’s investments in securities of foreign issuers or issuers with significant exposure to foreign markets involve additional risk. Foreign countries in which the fund or an underlying fund may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the fund or an underlying fund’s investments may decline because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable government actions, and political or financial instability. Lack of information may also affect the value of these securities.

The risks of foreign investments are heightened when investing in issuers in emerging market countries.

Currency risk. The value of investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency conversion costs and currency fluctuations could erase investment gains or add to investment losses. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Real estate investment trusts (REITs) risk. Investments in REITs expose an underlying fund to risks similar to investing directly in real estate, such as changes in the value of the underlying real estate, the quality of the property management, the creditworthiness of the issuer of the investments, and changes in property taxes, interest rates and the real estate regulatory environment.

Exchange-traded funds (ETFs) risk. Investing in an ETF will give the fund exposure to the securities comprising the index on which the ETF is based and will expose the fund to risks similar to those of investing directly in those securities. Shares of ETFs are traded on an exchange and may trade at either a premium or discount to net asset value. The fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

Valuation risk. The sales price the fund or an underlying fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities or other instruments that trade in thin or volatile markets or that are valued using a fair value methodology. Investors who purchase or redeem fund shares on days when the fund or an underlying fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the fund or the underlying fund had not fair-valued the security or had used a different valuation methodology.

Risk of increase in expenses. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if a fee limitation is changed or terminated or if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile.

These risks are discussed in more detail later in this Prospectus or in the SAI.

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class C shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year and also compares the fund’s performance with the average annual total returns of an index or other benchmark. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund also compares its performance to the Morgan Stanley Capital International (“MSCI”) Europe, Australasia, Far East (“EAFE”) Index, the Barclays U.S. Aggregate Index and a composite benchmark, which is a hypothetical representation of the performance of the fund’s major asset classes, consisting of 42% Barclays U.S. Aggregate Index (an index of fixed income securities), 15% Barclays Global Aggregate ex-USD Index (an index tracking an international basket of government, corporate, agency and mortgage-related bonds), 14% MSCI EAFE Index, 8% Russell 1000 Index, 8% Barclays U.S. Corporate High Yield-2% Issuer Cap Index (an index where issuer exposure is limited to 2% of the market value of the Barclays U.S. Corporate High Yield Index), 5% FTSE NAREIT All RElTs Index (an index of all tax-qualified exchange-listed REITs), 5% Russell 2000 Index and 3% MSCI Emerging Markets Index.

The fund makes updated performance information available at the fund’s website, http://www.leggmason.com/individualinvestors/products/mutual-funds/annualized_performance (select share class), or by calling the fund at 1-877-721-1926.

The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

Total returns (before taxes) (%)

Calendar Years ended December 31

Best quarter
(06/30/2009): 16.89

Worst quarter
(03/31/2009): (8.05)

The year-to-date return as of the most recent calendar quarter, which ended 3/31/13, was 1.95

Average annual total returns (for periods ended December 31, 2012) (%)

Average Annual Total Returns Legg Mason Target Retirement Fund	1 year	Since inception	Inception date
Class C	9.78%	6.49%	Aug. 29, 2008
Class C Return after taxes on distributions	9.28%	5.51%	Aug. 29, 2008
Class C Return after taxes on distributions and sale of fund shares	6.38%	4.98%	Aug. 29, 2008
Class A	5.24%	5.84%	Aug. 29, 2008
Class FI	11.63%	7.28%	Aug. 29, 2008
Class R	11.25%	7.01%	Aug. 29, 2008
Class I	11.98%	7.61%	Aug. 29, 2008
Russell 3000 Index (reflects no deduction for fees, expenses or taxes)	16.42%	4.99%
MSCI EAFE Index (Gross) (reflects no deduction for fees, expenses or taxes)	17.90%	0.51%
Barclays U.S. Aggregate Index (reflects no deduction for fees, expenses or taxes)	4.22%	6.41%
Target Retirement Fund Composite Index (reflects no deduction for fees, expenses or taxes)	9.93%	6.43%

The after-tax returns are shown only for Class C shares, are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for classes other than Class C will vary from returns shown for Class C.

[1] Generally,

[2] If your shares are held in a direct account and the value of your account is below $1,000 ($250 for retirement plans that are not employer-sponsored), the fund may charge you a fee of $3.75 per account that is determined and assessed quarterly (with an annual maximum of $15.00 per account). Direct accounts generally include accounts held in the name of the individual investor on the fund's books and records.

[1] "Other expenses" are estimated for the current fiscal year. Actual expenses may differ from estimates.

[2] Total annual fund operating expenses do not correlate with the ratios of expenses to average net assets reported in the financial highlights tables in the Prospectus and in the fund's shareholder reports, because the ratios in the financial highlights tables reflect the fund's operating expenses and do not include acquired fund fees and expenses.

[3] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses and brokerage, except for brokerage commissions paid on purchases and sales of shares of exchange-traded funds) so that total annual operating expenses are not expected to exceed 1.15% for Class A shares, 1.90% for Class C shares, 1.15% for Class FI shares, 1.40% for Class R shares, 1.90% for Class R1 shares, 0.85% for Class I shares and 0.75% for Class IS shares. These arrangements cannot be terminated prior to December 31, 2014 without the Board of Trustees' consent. The manager is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class' total annual operating expenses have fallen to a level below the limits described above.

XML

Document and Entity Information	12 Months Ended
	Jun. 01, 2013
Risk/Return:
Document Type	485BPOS
Document Period End Date	Jan. 31, 2013
Registrant Name	LEGG MASON PARTNERS EQUITY TRUST
Central Index Key	0000880366
Amendment Flag	false
Document Creation Date	May 21, 2013
Document Effective Date	Jun. 01, 2013
Prospectus Date	Jun. 01, 2013