XML 21 R7.htm IDEA: XBRL DOCUMENT v2.4.0.8
Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading ACTIVE ASSETS MONEY TRUST
Objective [Heading] rr_ObjectiveHeading Investment Objectives
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

Active Assets Money Trust is a money market fund that seeks to provide high current income, preservation of capital and liquidity.

Expense [Heading] rr_ExpenseHeading Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund. The Fund is a no-load fund. The Fund does not impose any sales charges.

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)
Expense Example [Heading] rr_ExpenseExampleHeading Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below 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, your investment has a 5% return each year, and the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading] rr_StrategyHeading Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

The Fund invests in high quality, short-term debt obligations. In selecting investments, the Adviser seeks to maintain the Fund's share price at $1.00. The Fund's investments include the following money market instruments: corporate obligations (including, but not limited to, commercial paper); debt obligations of U.S.-regulated banks (including domestic branches or subsidiaries of foreign banks) and instruments secured by those obligations (including certificates of deposit); certificates of deposit of savings banks and savings and loan associations; debt obligations issued or guaranteed as to principal and interest by the U.S. Government, its agencies or instrumentalities; asset-backed securities; U.S. dollar-denominated foreign bank obligations; repurchase agreements; and municipal obligations.

Risk [Heading] rr_RiskHeading Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

There is no assurance that the Fund will achieve its investment objectives. Although the Fund seeks to preserve the value of your investment at $1.00 per share, if it is unable to do so, it is possible to lose money by investing in the Fund. The principal risks of investing in the Fund include:


•  Credit and Interest Rate Risk. Credit risk refers to the possibility that the issuer or guarantor of a security will be unable to make interest payments and/or repay the principal on its debt. Interest rate risk refers to fluctuations in the value of a debt security resulting from changes in the general level of interest rates. The historically low interest rate environment increases the risk associated with rising interest rates.


•  U.S. Government Securities. With respect to U.S. government securities that are not backed by the full faith and credit of the United States, there is the risk that the U.S. Government will not provide financial support to such U.S. government agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law.


•  Asset-Backed Securities. Asset-backed securities involve the risk that the various federal and state consumer laws and other legal and economic factors may result in the collateral backing the securities being insufficient to support payment on the securities. Some asset-backed securities also entail prepayment risk, which may vary depending on the type of asset.


•  Foreign Money Market Securities. Investing in money market securities of foreign issuers involves some additional risks, including the possibility of adverse political, economic or other developments affecting the issuers of these securities.


•  Repurchase Agreements. Repurchase agreements are subject to risks associated with the possibility of default by the seller at a time when the collateral has declined in value, or insolvency of the seller, which may affect the Fund's right to control the collateral and result in certain costs and delays. Repurchase agreements may involve a greater degree of credit risk than investments in U.S. government securities.


•  Municipal Obligations. To the extent the Fund invests in municipal obligations issued by state and local governments and their agencies, the Fund may be susceptible to political, economic, regulatory or other factors affecting issuers of these municipal obligations.


Shares of the Fund are not bank deposits and are not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency.

Risk Money Market Fund [Text] rr_RiskMoneyMarketFund Although the Fund seeks to preserve the value of your investment at $1.00 per share, if it is unable to do so, it is possible to lose money by investing in the Fund.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution Shares of the Fund are not bank deposits and are not guaranteed or insured by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Past Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing the Fund's average annual returns for the one, five and 10 year periods. The Fund's past performance does not indicate how the Fund will perform in the future.

Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing the Fund's average annual returns for the one, five and 10 year periods.
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The Fund's past performance does not indicate how the Fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Annual Total Returns-Calendar Years
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

The year-to-date total return as of September 30, 2013 was 0.01%.


High Quarter

 

9/30/07

   

1.24

%

 

Low Quarter

 

6/30/09

   

0.00

%

 
Year to Date Return, Label rr_YearToDateReturnLabel year-to-date total return
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 0.01%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel High Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2007
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 1.24%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Low Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Jun. 30, 2009
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn 0.00%
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

For the Fund's most recent 7-day annualized yield you may call toll-free (800) 548-7786.

Caption rr_AverageAnnualReturnCaption Average Annual Total Returns (as of December 31, 2012)
Money Market Seven Day Yield Phone rr_MoneyMarketSevenDayYieldPhone (800) 548-7786
ACTIVE ASSETS MONEY TRUST
  
Risk/Return: rr_RiskReturnAbstract  
Advisory Fee rr_ManagementFeesOverAssets 0.25%
Distribution (12b-1) Fee rr_DistributionAndService12b1FeesOverAssets 0.10%
Other Expenses rr_OtherExpensesOverAssets 0.07%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.42%
Fee Waiver or Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.16%) [1]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements rr_NetExpensesOverAssets 0.26% [1]
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 27
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 84
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 146
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 331
Annual Return 2003 rr_AnnualReturn2003 0.78%
Annual Return 2004 rr_AnnualReturn2004 0.99%
Annual Return 2005 rr_AnnualReturn2005 2.85%
Annual Return 2006 rr_AnnualReturn2006 4.68%
Annual Return 2007 rr_AnnualReturn2007 5.01%
Annual Return 2008 rr_AnnualReturn2008 2.63%
Annual Return 2009 rr_AnnualReturn2009 0.03%
Annual Return 2010 rr_AnnualReturn2010 0.01%
Annual Return 2011 rr_AnnualReturn2011 0.01%
Annual Return 2012 rr_AnnualReturn2012 0.01%
Average Annual Returns, Past 1 Year rr_AverageAnnualReturnYear01 0.01%
Average Annual Returns, Past 5 Years rr_AverageAnnualReturnYear05 0.53%
Average Annual Returns, Past 10 Years rr_AverageAnnualReturnYear10 1.68%
[1] The Fund's "Distributor," Morgan Stanley Distribution, Inc., its "Adviser," Morgan Stanley Investment Management Inc., and its "Administrator," Morgan Stanley Services Company Inc., have agreed to waive and/or reimburse all or a portion of the Fund's distribution fee, advisory fee and administration fee, respectively, to the extent that total expenses exceed total income on a daily basis. These fee waivers and/or expense reimbursements will continue for at least one year or until such time as the Fund's Board of Trustees acts to discontinue all or a portion of such waivers and/or expense reimbursements when it deems such action appropriate.