These tables describe the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts in Class A if you and your family invest, or agree to invest in the future, at least $100,000 in Franklin Templeton funds. More information about these and other discounts is available from your financial professional and under “Your Account” on page 113 in the Fund's Prospectus and under “Buying and Selling Shares” on page 75 of the Fund’s Statement of Additional Information.

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)

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 Fund 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 4.87% of the average value of its portfolio.

Expense Breakpoint Discounts [Text]

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You may qualify for sales charge discounts in Class A if you and your family invest, or agree to invest in the future, at least $100,000 in Franklin Templeton funds.

Expense Breakpoint, Minimum Investment Required [Amount]

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$ 100,000

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 that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of the period. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The Example reflects adjustments made to the Fund's operating expenses due to the fee waiver and/or expense reimbursement by management for the 1 Year numbers only. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

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

rr_ExpenseExampleNoRedemptionByYearCaption

If you do not sell your shares:

Strategy [Heading]

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Principal Investment Strategies

Strategy Narrative [Text Block]

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Under normal market conditions, the Fund invests at least 80% of its net assets in “adjustable-rate U.S. government mortgage securities.” “Adjustable-rate U.S. government mortgage securities” include adjustable-rate mortgage securities (ARMS) and other mortgage-backed securities with interest rates that adjust periodically to reflect prevailing market interest rates, which are issued or guaranteed by the U.S. government, its agencies or instrumentalities, including government sponsored entities.

Mortgage-backed securities represent an interest in a pool of mortgage loans made by banks and other financial institutions to finance purchases of homes, commercial buildings and other real estate. As the underlying mortgage loans are paid off, investors receive periodic principal and interest payments as well as any unscheduled principal prepayments on the underlying mortgage loans. The mortgage-backed securities purchased by the Fund include bonds and notes issued or guaranteed by the Government National Mortgage Association (Ginnie Mae) and U.S. government-sponsored entities, such as the Federal National Mortgage Association (Fannie Mae) and the Federal Home Loan Mortgage Corporation (Freddie Mac). The Fund currently focuses on mortgage-backed securities issued or guaranteed by Fannie Mae and Freddie Mac.

Government agency or instrumentality issues have different levels of credit support. Ginnie Mae pass-through mortgage certificates are backed by the full faith and credit of the U.S. government. U.S. government-sponsored entities, such as Fannie Mae and Freddie Mac, may be chartered by Acts of Congress, but their securities are neither issued nor guaranteed by the U.S. government. Although the U.S. government has provided financial support to Fannie Mae and Freddie Mac, no assurance can be given that the U.S. government will continue to do so. Accordingly, securities issued by Fannie Mae and Freddie Mac may involve a risk of non-payment of principal and interest. Investors should remember that guarantees of timely prepayment of principal and interest do not apply to the market prices and yields of the securities or to the net asset value or performance of the Fund, which will vary with changes in interest rates and other market conditions. Any downgrade of the credit rating of the securities issued by the U.S. government may result in a downgrade of securities issued by its agencies or instrumentalities, including government-sponsored entities.

These periodic interest rate adjustments may help keep the prices of these securities relatively stable when compared with the prices of fixed-rate securities, which generally fall when interest rates rise. Adjustable-rate securities, however, frequently limit the maximum amount by which the interest rate may change up or down. The Fund, therefore, may not benefit from increases in interest rates if interest rates exceed a security’s maximum allowable periodic or lifetime limits. During periods of falling interest rates, the interest rates on these securities may reset downward, resulting in a lower yield for the Fund.

The Fund may invest up to 20% of its net assets in other securities, including fixed-rate mortgage-backed securities, mortgage-backed securities issued by a private entity, direct obligations of the U.S. government, such as Treasury bills, bonds or notes, and in repurchase agreements collateralized by U.S. government or government agency securities.

Strategy Portfolio Concentration [Text]

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Under normal market conditions, the Fund invests at least 80% of its net assets in “adjustable-rate U.S. government mortgage securities.”

Risk [Heading]

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Principal Risks

Risk Narrative [Text Block]

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You could lose money by investing in the Fund. Mutual fund shares are not deposits or obligations of, or guaranteed or endorsed by, any bank, and are not insured by the Federal Deposit Insurance Corporation, the Federal Reserve Board, or any other agency of the U.S. government.

Interest Rate

When interest rates rise, debt security prices generally fall. The opposite is also generally true: debt security prices rise when interest rates fall. In general, securities with longer maturities are more sensitive to these interest rate changes.

Mortgage-Backed Securities

Mortgage-backed securities differ from conventional debt securities because principal is paid back periodically over the life of the security rather than at maturity. The Fund may receive unscheduled payments of principal due to voluntary prepayments, refinancings or foreclosures on the underlying mortgage loans. Because of prepayments, mortgage-backed securities may be less effective than some other types of debt securities as a means of "locking in" long-term interest rates and may have less potential for capital appreciation during periods of falling interest rates. A reduction in the anticipated rate of principal prepayments, especially during periods of rising interest rates, may increase or extend the effective maturity of mortgage-backed securities, making them more sensitive to interest rate changes, subject to greater price volatility, and more susceptible than some other debt securities to a decline in market value when interest rates rise.

Adjustable Rate Securities

Because changes in interest rates on adjustable rate securities may lag behind changes in market rates, the value of such securities may decline during periods of rising interest rates until their interest rates reset to market rates. If the changes in market rates are substantial, the interest rate on an adjustable rate security may not reset during a single adjustment period. Lifetime limits on resets may also prevent their rates from adjusting to market rates.

During periods of declining interest rates, because the interest rates on adjustable rate securities generally reset downward, their market value is unlikely to rise to the same extent as the value of comparable fixed rate securities.

Credit

An issuer of debt securities may fail to make interest payments and repay principal when due, in whole or in part. Changes in an issuer's financial strength or in a security's credit rating may affect a security's value. While securities issued by Ginnie Mae are backed by the full faith and credit of the U.S. government, not all securities of the various U.S. government agencies are, including those of Fannie Mae and Freddie Mac. Also guarantees of principal and interest do not apply to market prices, yields or the Fund’s share price. While the U.S. government has provided financial support to Fannie Mae and Freddie Mac, no assurance can be given that the U.S. government will always do so, since the U.S. government is not so obligated by law. Accordingly, securities issued by Fannie Mae and Freddie Mac may involve a risk of non-payment of principal and interest. Any downgrade of the credit rating of the securities issued by the U.S. government may result in a downgrade of securities issued by its agencies or instrumentalities, including government-sponsored entities.

Prepayment

Prepayment risk occurs when a debt security can be repaid in whole or in part prior to the security's maturity and the Fund must reinvest the proceeds it receives, during periods of declining interest rates, in securities that pay a lower rate of interest.

Extension Risk

Some debt securities, particularly mortgage-backed securities, are subject to the risk that the debt security’s effective maturity is extended because calls or prepayments are less or slower than anticipated, particularly when interest rates rise. The market value of such security may then decline and become more interest rate sensitive.

Income

Because the Fund can only distribute what it earns, the Fund's distributions to shareholders may decline when prevailing interest rates fall or when the Fund experiences defaults on debt securities it holds.

Market

The market values of securities owned by the Fund will go up or down, sometimes rapidly or unpredictably. A security’s market value may be reduced by market activity or other results of supply and demand unrelated to the issuer. This is a basic risk associated with all securities. When there are more sellers than buyers, prices tend to fall. Likewise, when there are more buyers than sellers, prices tend to rise.

Management

The Fund is subject to management risk because it is an actively managed investment portfolio. The Fund's investment manager applies investment techniques and risk analyses in making investment decisions for the Fund, but there can be no guarantee that these decisions will produce the desired results.

Bar Chart and Performance Table [Heading]

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Performance

Performance Narrative [Text Block]

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The following 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 how the Fund's average annual returns for 1 year, 5 years, 10 years or since inception, as applicable, compared with those of a broad measure of market performance. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. You can obtain updated performance information at franklintempleton.com or by calling (800) DIAL BEN/342-5236.

Sales charges are not reflected in the 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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Performance Availability Phone [Text]

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(800) DIAL BEN/342-5236

Performance Availability Website Address [Text]

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franklintempleton.com

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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CLASS A ANNUAL TOTAL RETURNS

Bar Chart Does Not Reflect Sales Loads [Text]

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

Bar Chart Closing [Text Block]

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Best Quarter:	Q1'09	1.72%
Worst Quarter:	Q4'12	-0.39%
As of June 30, 2013, the Fund's year-to-date return was -0.05%.

Performance Table Heading

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AVERAGE ANNUAL TOTAL RETURNS
(figures reflect sales charges)

For the periods ended December 31, 2012

Performance Table Closing [Text Block]

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Performance information for Class R6 shares is not shown because it had not commenced operations as of the date of this prospectus.

Historical performance for Advisor Class shares prior to their inception is based on the performance of Class A shares. Advisor Class performance has been adjusted to reflect differences in sales charges between classes.

The after-tax returns 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. After-tax returns 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 are shown only for Class A and after-tax returns for other classes will vary.

Franklin Adjustable U.S. Government Securities Fund | Barclays U.S. Government Index: 1-2 Year Component

Risk/Return:

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1 Year

rr_AverageAnnualReturnYear01

0.37%

5 Years

rr_AverageAnnualReturnYear05

2.04%

10 Years

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2.56%

Franklin Adjustable U.S. Government Securities Fund | Class A

Risk/Return:

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Maximum Cumulative Sales Charge (as a percentage of Offering Price)

rr_MaximumCumulativeSalesChargeOverOfferingPrice

2.25%

Maximum Deferred Sales Charge (as a percentage of Offering Price)

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none

Management Fees (as a percentage of Assets)

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other Expenses (as a percentage of Assets):

rr_OtherExpensesOverAssets

0.12%

^[1]

Expenses (as a percentage of Assets)

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0.87%

Expense Example, with Redemption, 1 Year

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312

Expense Example, with Redemption, 3 Years

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496

Expense Example, with Redemption, 5 Years

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696

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,273

Annual Return 2003

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1.23%

Annual Return 2004

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1.79%

Annual Return 2005

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2.06%

Annual Return 2006

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4.15%

Annual Return 2007

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5.03%

Annual Return 2008

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3.58%

Annual Return 2009

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4.35%

Annual Return 2010

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1.29%

Annual Return 2011

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1.72%

Annual Return 2012

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1.42%

Year to Date Return, Label

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As of June 30, 2013, the Fund's year-to-date return was -0.05%.

Highest Quarterly Return, Label

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Best Quarter:

Highest Quarterly Return, Date

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Mar. 31, 2009

Highest Quarterly Return

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1.72%

Lowest Quarterly Return, Label

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Worst Quarter:

Lowest Quarterly Return, Date

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Dec. 31, 2012

Lowest Quarterly Return

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(0.39%)

Label

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Return Before Taxes

1 Year

rr_AverageAnnualReturnYear01

(0.82%)

5 Years

rr_AverageAnnualReturnYear05

2.01%

10 Years

rr_AverageAnnualReturnYear10

2.42%

Franklin Adjustable U.S. Government Securities Fund | Class A | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

1 Year

rr_AverageAnnualReturnYear01

(1.35%)

5 Years

rr_AverageAnnualReturnYear05

1.11%

10 Years

rr_AverageAnnualReturnYear10

1.30%

Franklin Adjustable U.S. Government Securities Fund | Class A | After Taxes on Distributions and Sales

Risk/Return:

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1 Year

rr_AverageAnnualReturnYear01

(0.53%)

5 Years

rr_AverageAnnualReturnYear05

1.19%

10 Years

rr_AverageAnnualReturnYear10

1.40%

Franklin Adjustable U.S. Government Securities Fund | Class C

Risk/Return:

rr_RiskReturnAbstract

Maximum Cumulative Sales Charge (as a percentage of Offering Price)

rr_MaximumCumulativeSalesChargeOverOfferingPrice

none

Maximum Deferred Sales Charge (as a percentage of Offering Price)

rr_MaximumDeferredSalesChargeOverOfferingPrice

1.00%

Management Fees (as a percentage of Assets)

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.65%

Other Expenses (as a percentage of Assets):

rr_OtherExpensesOverAssets

0.12%

^[1]

Expenses (as a percentage of Assets)

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1.27%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

229

Expense Example, with Redemption, 3 Years

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403

Expense Example, with Redemption, 5 Years

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697

Expense Example, with Redemption, 10 Years

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1,534

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

129

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

403

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

697

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

1,534

1 Year

rr_AverageAnnualReturnYear01

0.13%

5 Years

rr_AverageAnnualReturnYear05

2.08%

10 Years

rr_AverageAnnualReturnYear10

2.27%

^[2]

Franklin Adjustable U.S. Government Securities Fund | Class R6

Risk/Return:

rr_RiskReturnAbstract

Maximum Cumulative Sales Charge (as a percentage of Offering Price)

rr_MaximumCumulativeSalesChargeOverOfferingPrice

none

^[3]

Maximum Deferred Sales Charge (as a percentage of Offering Price)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[3]

Management Fees (as a percentage of Assets)

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses (as a percentage of Assets):

rr_OtherExpensesOverAssets

0.04%

^[1]

Expenses (as a percentage of Assets)

rr_ExpensesOverAssets

0.54%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

173

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

302

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

677

Franklin Adjustable U.S. Government Securities Fund | Advisor Class

Risk/Return:

rr_RiskReturnAbstract

Maximum Cumulative Sales Charge (as a percentage of Offering Price)

rr_MaximumCumulativeSalesChargeOverOfferingPrice

none

Maximum Deferred Sales Charge (as a percentage of Offering Price)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management Fees (as a percentage of Assets)

rr_ManagementFeesOverAssets

0.50%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses (as a percentage of Assets):

rr_OtherExpensesOverAssets

0.12%

^[1]

Expenses (as a percentage of Assets)

rr_ExpensesOverAssets

0.62%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

199

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

346

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 774

1 Year

rr_AverageAnnualReturnYear01

1.68%

5 Years

rr_AverageAnnualReturnYear05

2.72%

10 Years

rr_AverageAnnualReturnYear10

2.78%

^[4]

[1]	Other expenses for Class R6 represent an estimate of expenses, including the effect of this Class's lower shareholder servicing fees.
[2]	Since inception July 1, 2003.
[3]	The Fund will begin offering Class R6 shares on September 20, 2013.
[4]	Since inception May 15, 2008.