485BPOS

As filed with the Securities and Exchange Commission on February 8, 2013

1933 Act Registration No. 333-162441

1940 Act Registration No. 811-22338

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. 55	x
and

REGISTRATION STATEMENT

UNDER

THE INVESTMENT COMPANY ACT OF 1940	x
Amendment No. 54	x

LEGG MASON GLOBAL ASSET MANAGEMENT TRUST

(Exact Name of Registrant as Specified in Charter)

100 International Drive

Baltimore, Maryland 21202

(Address of principal executive offices)

Registrant’s telephone number, including area code: (410) 539-0000

Name and address of agent for service:	Copy to:
RICHARD M. WACHTERMAN, ESQ. Legg Mason & Co., LLC 100 International Drive Baltimore, Maryland 21202	ARTHUR C. DELIBERT, ESQ. K&L Gates LLP 1601 K Street, N.W. Washington, D.C. 20006-1600
(Name and address of agent for service)

Approximate Date of Proposed Public Offering: Continuous

It is proposed that this filing will become effective:

x immediately upon filing pursuant to Rule 485(b)

¨ on                     , pursuant to Rule 485(b)

¨ 60 days after filing pursuant to Rule 485 (a)(1)

¨ on                     , pursuant to Rule 485 (a)(1)

¨ 75 days after filing pursuant to Rule 485(a)(2)

¨ on, pursuant to Rule 485(a)(2)

If appropriate, check the following box:

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

This amendment is being filed solely to submit exhibits containing risk/return summary information in interactive data format that is identical to the risk/return information contained in the Registrant’s prospectus for Legg Mason BW Diversified Large Cap Value Fund, which was filed with the Securities and Exchange Commission in Post-Effective Amendment No. 54 (“PEA 54”) to the Registrant’s registration statement on January 25, 2013.

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 GLOBAL ASSET MANAGEMENT TRUST, hereby certifies that it meets all the requirements for effectiveness of this Post-Effective Amendment No. 55 to its Registration Statement under Rule 485(b) under the Securities Act and has duly caused this Post-Effective Amendment No. 55 to its Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Baltimore, State of Maryland on this 8^th day of February, 2013.

LEGG MASON GLOBAL ASSET MANAGEMENT TRUST, on behalf of Legg Mason BW Diversified Large Cap Value Fund

By:	/s/ R. Jay Gerken
	R. Jay Gerken
	President

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 February 8, 2013.

Signature	Title
/s/ R. Jay Gerken	President (Principal Executive Officer) and Trustee
R. Jay Gerken
/s/ Ruby P. Hearn*	Trustee
Ruby P. Hearn
/s/ Arnold L. Lehman *	Trustee
Arnold L. Lehman
/s/ Robin J.W. Masters *	Trustee
Robin J.W. Masters
/s/ Jill E. McGovern*	Trustee
Jill E. McGovern
/s/ Arthur S. Mehlman *	Trustee
Arthur S. Mehlman
/s/ G. Peter O’Brien *	Trustee
G. Peter O’Brien
/s/ S. Ford Rowan*	Trustee
S. Ford Rowan
/s/ Robert M. Tarola *	Trustee
Robert M. Tarola
/s/ Richard F. Sennett	Principal Financial and Accounting Officer
Richard F. Sennett

* By:	/s/ Richard M. Wachterman
	Richard M. Wachterman

Attorney in Fact, pursuant to Power of Attorney filed herewith.

POWER OF ATTORNEY

I, the undersigned Director/Trustee of one or more of the following investment companies (as set forth in the companies’ Registration Statements on Form N-1A):

LEGG MASON INCOME TRUST, INC.	LEGG MASON CHARLES STREET TRUST, INC.
LEGG MASON GLOBAL TRUST, INC.	LEGG MASON GLOBAL ASSET MANAGEMENT TRUST
LEGG MASON TAX-FREE INCOME FUND	LEGG MASON INVESTORS TRUST, INC.
LEGG MASON CAPITAL MANAGEMENT GROWTH TRUST, INC.	LEGG MASON LIGHT STREET TRUST, INC.
LEGG MASON CAPITAL MANAGEMENT VALUE TRUST, INC.	LEGG MASON INVESTMENT TRUST, INC.
LEGG MASON INVESTMENT TRUST
LEGG MASON CAPITAL MANAGEMENT SPECIAL INVESTMENT TRUST, INC.

plus any other investment company for which Legg Mason Partners Fund Advisor, LLC or an affiliate thereof acts as investment adviser or manager and for which the undersigned individual serves as Director/Trustee hereby severally constitute and appoint each of R. JAY GERKEN, RICHARD SENNETT, ERIN K. MORRIS, CHRISTOPHER BERARDUCCI, ROBERT I. FRENKEL, RICHARD M. WACHTERMAN, THOMAS C. MANDIA, MARC A. DE OLIVERIA, MICHAEL KOCUR, ARTHUR C. DELIBERT and NDENISARYA M. BREGASI my true and lawful attorney-in-fact, with full power of substitution, and each with full power to sign for me and in my name in the appropriate capacity and only for those companies described above for which I serve as Director/Trustee, any Registration Statements on Form N-1A, all Pre-Effective Amendments to any Registration Statements of the Funds, any and all Post-Effective Amendments to said Registration Statements, and any and all supplements or other instruments in connection therewith, to file the same with the Securities and Exchange Commission and the securities regulators of appropriate states and territories, and generally to do all such things in my name and behalf in connection therewith as said attorney-in-fact deems necessary or appropriate to comply with the provisions of the Securities Act of 1933 and the Investment Company Act of 1940, all related requirements of the Securities and Exchange Commission and all requirements of appropriate states and territories. I hereby ratify and confirm all that said attorney-in-fact or their substitutes may do or cause to be done by virtue hereof.

Any subsequently executed power of attorney that grants powers unrelated to the powers granted herein will not revoke nor supersede this power of attorney unless such subsequent power of attorney expressly states otherwise.

WITNESS my hand on the date set forth below at Baltimore, Maryland.

SIGNATURE	DATE
/s/ Mark R. Fetting	February 23, 2012
Mark R. Fetting
/s/ R. Jay Gerken	February 23, 2012
R. Jay Gerken
/s/ Ruby P. Hearn	February 23, 2012
Ruby P. Hearn
/s/ Arnold L. Lehman	February 23, 2012
Arnold L. Lehman
/s/ Robin J.W. Masters	February 23, 2012
Robin J.W. Masters
/s/ Jill E. McGovern	February 23, 2012
Jill E. McGovern
/s/ Arthur S. Mehlman	February 23, 2012
Arthur S. Mehlman
/s/ Jennifer W. Murphy	February 23, 2012
Jennifer W. Murphy
/s/ G. Peter O’Brien	February 23, 2012
G. Peter O’Brien
/s/ S. Ford Rowan	February 23, 2012
S. Ford Rowan
/s/ Robert M. Tarola	February 23, 2012
Robert M. Tarola

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 Global Asset Management Trust
Prospectus Date	rr_ProspectusDate	Feb. 01, 2013
Legg Mason BW Diversified Large Cap Value Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Legg Mason BW Diversified Large Cap Value Fund
Objective [Heading]	rr_ObjectiveHeading	Investment objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Long-term capital appreciation.
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 18 under the heading “Sales charges” and in the fund’s statement of additional information (“SAI”) on page 36 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 indicates 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 38% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	38.00%
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” for Class A2, FI, R and R1 are based on estimated amounts for the current fiscal year. Actual expenses may differ from estimates.
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 normally invests at least 80% of its net assets in equity securities of large capitalization companies. Large capitalization companies are those companies with market capitalizations similar to companies in the Russell 1000® Index (the “Index”). The size of the companies in the Index changes with market conditions and the composition of the Index. As of November 30, 2012, the median market capitalization of a company in the Index was approximately $5.634 billion and the dollar-weighted average market capitalization of the companies in the Index was approximately $98.862 billion. The fund invests primarily in equity securities that, in the investment adviser’s opinion, are undervalued or out of favor. The investment adviser invests in securities that meet its value criteria, primarily, price-to-earnings, price-to-book, price momentum and share change and quality, based on both quantitative and fundamental analysis. The fund expects to hold approximately 150-250 stocks under normal market conditions. The fund may invest in foreign equity securities, either directly or through depositary receipts. The fund may take temporary defensive and cash management positions; in such a case, the fund will not be pursuing its principal investment strategies and may not achieve its investment objective.
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. Stock market and equity securities risk. The securities markets are volatile and the market prices of the 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 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. 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. 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. 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. The 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. Portfolio selection risk. The value of your investment may decrease if the adviser's judgment about the attractiveness or value of or market trends affecting a particular security, industry, sector, or region, or about interest rates is incorrect. Model risk. The adviser’s investment models may not adequately take into account certain factors and may result in the fund having a lower return than if the fund were managed using another model or investment strategy. Value investing risk. The value approach to investing involves the risk that stocks may remain undervalued or decline in price. Value stocks may underperform the overall equity market while the market concentrates on growth stocks. Although the fund will not concentrate its investments in any one industry or industry group, it may, like many value funds, weight its investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries. Market sector risk. The fund may be significantly overweight or underweight certain companies, industries or market sectors, which may cause the fund’s performance to be more sensitive to developments affecting those companies, industries or sectors. Large capitalization company risk. Large capitalization companies may fall out of favor with investors. Foreign investments risk. The 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 may invest may have markets that are less liquid, less regulated and more volatile than U.S. markets. The value of the 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. Because the value of a depositary receipt is dependent upon the market price of an underlying foreign security, depositary receipts are subject to most of the risks associated with investing in foreign securities directly. 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. Special risks of companies undergoing reorganization or restructuring. Investing in companies undergoing reorganization or restructuring involves special risks including that the transaction may not be completed on the terms or time frame contemplated (if at all), it may be difficult to obtain information on the financial condition of such companies, the issuer’s management may be addressing a type of situation with which it has little experience, and the fact that the market prices of such securities are subject to above-average price volatility. Cash management and defensive investing risk. The value of the investments held by the fund for cash management or defensive investing purposes 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 a significant amount of the fund’s assets are used for cash management or defensive investing purposes, it may not achieve its investment objective. Valuation risk. The sales price the fund could receive for any particular portfolio investment may differ from the fund’s valuation of the investment, particularly for securities 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 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 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. Funds of funds investments risk. The fund may be an investment option for other Legg Mason-advised mutual funds that are managed as “funds of funds.” As a result, from time to time, the fund may experience relatively large redemptions or investments and could be required to sell securities or to invest cash at a time when it is not advantageous to do so. * * * 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 A 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 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 A 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 (ended 12/31/2011): 13.10 Worst quarter (ended 09/30/2011): (13.65)
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 A 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	After-tax returns for classes other than Class A will vary from returns shown for Class A.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The after-tax returns are shown only for Class A 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 A will vary from returns shown for Class A.
Legg Mason BW Diversified Large Cap Value 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)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Small account fee ($)	rr_MaximumAccountFee	15	[2]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.38%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.38%
Fees waived and/or expenses reimbursed	rr_FeeWaiverOrReimbursementOverAssets	(0.08%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses	rr_NetExpensesOverAssets	1.30%	[3]
1 year	rr_ExpenseExampleYear01	700
3 years	rr_ExpenseExampleYear03	979
5 years	rr_ExpenseExampleYear05	1,279
10 years	rr_ExpenseExampleYear10	2,130
1 year	rr_ExpenseExampleNoRedemptionYear01	700
3 years	rr_ExpenseExampleNoRedemptionYear03	979
5 years	rr_ExpenseExampleNoRedemptionYear05	1,279
10 years	rr_ExpenseExampleNoRedemptionYear10	2,130
2011	rr_AnnualReturn2011	5.43%
2012	rr_AnnualReturn2012	14.76%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Dec. 31, 2011
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	13.10%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(13.65%)
1 year	rr_AverageAnnualReturnYear01	8.13%
Since inception	rr_AverageAnnualReturnSinceInception	11.75%
Inception date	rr_AverageAnnualReturnInceptionDate	Sep. 07, 2010
Legg Mason BW Diversified Large Cap Value Fund | Class A2
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)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Small account fee ($)	rr_MaximumAccountFee	15	[2]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.58%	[4]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.58%
Fees waived and/or expenses reimbursed	rr_FeeWaiverOrReimbursementOverAssets	(0.08%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses	rr_NetExpensesOverAssets	1.50%	[3]
1 year	rr_ExpenseExampleYear01	719
3 years	rr_ExpenseExampleYear03	1,038
5 years	rr_ExpenseExampleYear05	1,379
10 years	rr_ExpenseExampleYear10	2,338
1 year	rr_ExpenseExampleNoRedemptionYear01	719
3 years	rr_ExpenseExampleNoRedemptionYear03	1,038
5 years	rr_ExpenseExampleNoRedemptionYear05	1,379
10 years	rr_ExpenseExampleNoRedemptionYear10	2,338
Legg Mason BW Diversified Large Cap Value Fund | Class C
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption)	rr_MaximumDeferredSalesChargeOverOther	1.00%
Small account fee ($)	rr_MaximumAccountFee	15	[2]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	0.36%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.11%
Fees waived and/or expenses reimbursed	rr_FeeWaiverOrReimbursementOverAssets	(0.06%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses	rr_NetExpensesOverAssets	2.05%	[3]
1 year	rr_ExpenseExampleYear01	308
3 years	rr_ExpenseExampleYear03	655
5 years	rr_ExpenseExampleYear05	1,128
10 years	rr_ExpenseExampleYear10	2,436
1 year	rr_ExpenseExampleNoRedemptionYear01	208
3 years	rr_ExpenseExampleNoRedemptionYear03	655
5 years	rr_ExpenseExampleNoRedemptionYear05	1,128
10 years	rr_ExpenseExampleNoRedemptionYear10	2,436
1 year	rr_AverageAnnualReturnYear01	12.87%
Since inception	rr_AverageAnnualReturnSinceInception	13.78%
Legg Mason BW Diversified Large Cap Value 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)	rr_MaximumDeferredSalesChargeOverOther	none
Small account fee ($)	rr_MaximumAccountFee	none	[2]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.58%	[4]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.58%
Fees waived and/or expenses reimbursed	rr_FeeWaiverOrReimbursementOverAssets	(0.28%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses	rr_NetExpensesOverAssets	1.30%	[3]
1 year	rr_ExpenseExampleYear01	132
3 years	rr_ExpenseExampleYear03	471
5 years	rr_ExpenseExampleYear05	833
10 years	rr_ExpenseExampleYear10	1,854
1 year	rr_ExpenseExampleNoRedemptionYear01	132
3 years	rr_ExpenseExampleNoRedemptionYear03	471
5 years	rr_ExpenseExampleNoRedemptionYear05	833
10 years	rr_ExpenseExampleNoRedemptionYear10	1,854
Legg Mason BW Diversified Large Cap Value Fund | Class R
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption)	rr_MaximumDeferredSalesChargeOverOther	none
Small account fee ($)	rr_MaximumAccountFee	none	[2]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.50%
Other expenses	rr_OtherExpensesOverAssets	0.58%	[4]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.83%
Fees waived and/or expenses reimbursed	rr_FeeWaiverOrReimbursementOverAssets	(0.28%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses	rr_NetExpensesOverAssets	1.55%	[3]
1 year	rr_ExpenseExampleYear01	158
3 years	rr_ExpenseExampleYear03	548
5 years	rr_ExpenseExampleYear05	964
10 years	rr_ExpenseExampleYear10	2,125
1 year	rr_ExpenseExampleNoRedemptionYear01	158
3 years	rr_ExpenseExampleNoRedemptionYear03	548
5 years	rr_ExpenseExampleNoRedemptionYear05	964
10 years	rr_ExpenseExampleNoRedemptionYear10	2,125
Legg Mason BW Diversified Large Cap Value 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)	rr_MaximumDeferredSalesChargeOverOther	none
Small account fee ($)	rr_MaximumAccountFee	none	[2]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	0.58%	[4]
Total annual fund operating expenses	rr_ExpensesOverAssets	2.33%
Fees waived and/or expenses reimbursed	rr_FeeWaiverOrReimbursementOverAssets	(0.28%)
Total annual fund operating expenses after waiving fees and/or reimbursing expenses	rr_NetExpensesOverAssets	2.05%	[3]
1 year	rr_ExpenseExampleYear01	208
3 years	rr_ExpenseExampleYear03	701
5 years	rr_ExpenseExampleYear05	1,220
10 years	rr_ExpenseExampleYear10	2,644
1 year	rr_ExpenseExampleNoRedemptionYear01	208
3 years	rr_ExpenseExampleNoRedemptionYear03	701
5 years	rr_ExpenseExampleNoRedemptionYear05	1,220
10 years	rr_ExpenseExampleNoRedemptionYear10	2,644
Legg Mason BW Diversified Large Cap Value Fund | Class I
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a % of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) (as a % of the lower of net asset value at purchase or redemption)	rr_MaximumDeferredSalesChargeOverOther	none
Small account fee ($)	rr_MaximumAccountFee	none	[2]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.19%
Total annual fund operating expenses	rr_ExpensesOverAssets	0.94%
Fees waived and/or expenses reimbursed	rr_FeeWaiverOrReimbursementOverAssets
Total annual fund operating expenses after waiving fees and/or reimbursing expenses	rr_NetExpensesOverAssets	0.94%	[3]
1 year	rr_ExpenseExampleYear01	97
3 years	rr_ExpenseExampleYear03	301
5 years	rr_ExpenseExampleYear05	521
10 years	rr_ExpenseExampleYear10	1,156
1 year	rr_ExpenseExampleNoRedemptionYear01	97
3 years	rr_ExpenseExampleNoRedemptionYear03	301
5 years	rr_ExpenseExampleNoRedemptionYear05	521
10 years	rr_ExpenseExampleNoRedemptionYear10	1,156
1 year	rr_AverageAnnualReturnYear01	15.10%
Since inception	rr_AverageAnnualReturnSinceInception	15.02%
Legg Mason BW Diversified Large Cap Value 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)	rr_MaximumDeferredSalesChargeOverOther	none
Small account fee ($)	rr_MaximumAccountFee	none	[2]
Management fees	rr_ManagementFeesOverAssets	0.75%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.09%
Total annual fund operating expenses	rr_ExpensesOverAssets	0.84%
Fees waived and/or expenses reimbursed	rr_FeeWaiverOrReimbursementOverAssets
Total annual fund operating expenses after waiving fees and/or reimbursing expenses	rr_NetExpensesOverAssets	0.84%	[3]
1 year	rr_ExpenseExampleYear01	86
3 years	rr_ExpenseExampleYear03	268
5 years	rr_ExpenseExampleYear05	466
10 years	rr_ExpenseExampleYear10	1,038
1 year	rr_ExpenseExampleNoRedemptionYear01	86
3 years	rr_ExpenseExampleNoRedemptionYear03	268
5 years	rr_ExpenseExampleNoRedemptionYear05	466
10 years	rr_ExpenseExampleNoRedemptionYear10	1,038
1 year	rr_AverageAnnualReturnYear01	15.09%
Since inception	rr_AverageAnnualReturnSinceInception	15.11%
Legg Mason BW Diversified Large Cap Value Fund | Return after taxes on distributions | Class A
Risk/Return:	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	6.49%
Since inception	rr_AverageAnnualReturnSinceInception	10.65%
Legg Mason BW Diversified Large Cap Value Fund | Return after taxes on distributions and sale of fund shares | Class A
Risk/Return:	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	5.67%
Since inception	rr_AverageAnnualReturnSinceInception	9.52%
Legg Mason BW Diversified Large Cap Value Fund | Russell 1000 Value Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	17.51%
Since inception	rr_AverageAnnualReturnSinceInception	13.96%

[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] The manager has agreed to waive fees and/or reimburse operating expenses (other than interest, taxes, extraordinary expenses, brokerage commissions and acquired fund fees and expenses) so that total annual operating expenses are not expected to exceed 1.30%, 1.50%, 2.05%, 1.30%, 1.55%, 2.05%, 0.95% and 0.85% for Class A, A2, C, FI, R, R1, I and IS shares, respectively, subject to recapture as described below. In addition, total annual fund operating expenses for Class IS shares will not exceed total annual fund operating expenses for Class I shares, subject to recapture as described below. These arrangements cannot be terminated prior to December 31, 2014 without the Board's consent. The manager currently intends to voluntarily waive fees and/or reimburse operating expenses (other than interest, brokerage commissions, dividend expense on short sales, taxes, extraordinary expenses and acquired fund fees and expenses) so that total annual operating expenses are not expected to exceed 1.10%, 1.30%, 1.85%, 1.10%, 1.35% and 0.85% for Class A, A2, C, FI, R and I shares, respectively. These arrangements are expected to continue until December 31, 2014 but may be terminated at any time by the manager. The manager is permitted to recapture amounts waived and/or reimbursed to a class within three years after the fiscal year in which the manager earned the fee or incurred the expense if the class' total annual operating expenses have fallen to a level below the limits described above.

[4] "Other expenses" for Class A2, FI, R and R1 are based on estimated amounts for the current fiscal year. Actual expenses may differ from estimates.