Label	Element	Value
Risk Return [Abstract]	rr_RiskReturnAbstract
ProspectusDate	rr_ProspectusDate	Jan. 31, 2012
SIMT Prime Obligation Fund (Prospectus Summary) | SIMT Prime Obligation Fund
Risk Return [Abstract]	rr_RiskReturnAbstract
Risk/Return, Heading	rr_RiskReturnHeading	PRIME OBLIGATION FUND
Investment Objective, Heading	rr_ObjectiveHeading	Investment Goal
investment Objective, Primary	rr_ObjectivePrimaryTextBlock	Preserving principal value and maintaining a high degree of liquidity while providing current income.
Expense, Heading	rr_ExpenseHeading	Fees and Expenses
Expense, Narrative	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold Fund shares.
Operating Expenses, Caption	rr_OperatingExpensesCaption	ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Other Expenses, New Fund, Based on Estimates	rr_OtherExpensesNewFundBasedOnEstimates	Other expenses are based on estimated amounts for the current fiscal year.
Expense Example, Heading	rr_ExpenseExampleHeading	EXAMPLE
Expense Example, Narrative	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 that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same.
Expense Example, By Year, Caption	rr_ExpenseExampleByYearCaption	Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Investment Strategy, Heading	rr_StrategyHeading	Principal Investment Strategies
Investment Strategy, Narrative	rr_StrategyNarrativeTextBlock	The Prime Obligation Fund is composed of short-term debt obligations of U.S. issuers that are rated in one of the two highest rating categories by a Nationally Recognized Statistical Rating Organization or that the Fund's sub-adviser (the Sub-Adviser) determines are of comparable quality. Under normal market conditions, the Fund invests in: (i) commercial paper and other short-term corporate obligations (including asset-backed securities) rated in the highest short-term rating category or that the Sub-Adviser determines are of comparable quality; (ii) certificates of deposit, time deposits, bankers' acceptances, bank notes and other obligations of U.S. commercial banks or savings and loan institutions that meet certain asset requirements; (iii) short-term obligations issued by state and local governments; and (iv) U.S. Treasury obligations and obligations issued or guaranteed as to principal and interest by agencies or instrumentalities of the U.S. Government. The Fund may also enter into fully-collateralized repurchase agreements. Using a top-down strategy and bottom-up security selection, the Sub-Adviser seeks securities with an acceptable maturity (a dollar-weighted average portfolio maturity of no more than 60 days and a remaining maturity of no greater than 397 days, consistent with requirements of the Investment Company Act of 1940, as amended, (the 1940 Act) for money market funds) that are marketable and liquid, offer competitive yields and are issued by issuers that are on a sound financial footing. The Sub-Adviser also considers factors such as the anticipated level of interest rates and the maturity of individual securities relative to the maturity of the Fund as a whole. The Fund follows the strict 1940 Act rules about the credit quality, maturity and diversification of its investments. With respect to credit quality and maturity, the Fund's investment guidelines may be more restrictive than the 1940 Act rules applicable to money market funds.
Risk, Heading	rr_RiskHeading	Principal Risks
Risk, Narrative	rr_RiskNarrativeTextBlock	An investment in the Fund is not a bank deposit nor is it insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Although the Fund seeks to maintain a constant price per share of $1.00, you may lose money by investing in the Fund. Interest Rate Risk - The risk that the Fund's yield will decline due to falling interest rates. A rise in interest rates typically causes the value of fixed income securities in which the Fund invests to fall in , while a fall in interest rates typically causes the value of such securities to rise. The Fund is also subject to the following additional risks: Asset-Backed Securities Risk - Payment of principal and interest on asset-backed securities is dependent largely on the cash flows generated by the assets backing the securities, and asset-backed securities may not have the benefit of any security interest in the related assets. Credit Risk - The risk that the issuer of a security or the counterparty to a contract will default or otherwise become unable to honor a financial obligation. Extension Risk - The risk that rising interest rates may extend the duration of a fixed income security, typically reducing the security's value. Foreign Issuer Risk - The risk that non-U.S. securities may be subject to additional risks due to, among other things, political, social and economic developments abroad, currency movements and different legal, regulatory and tax environments. Liquidity Risk - The risk that certain securities may be difficult or impossible to sell at the time and the price that the Fund would like. The Fund may have to lower the price, sell other securities instead or forego an investment opportunity, any of which could have a negative effect on Fund management or performance. Market Risk - The risk that the market value of a security may move up and down, sometimes rapidly and unpredictably. Market risk may affect a single issuer, an industry, a sector or the bond market as a whole. Opportunity Risk - The risk of missing out on an investment opportunity because the assets necessary to take advantage of that opportunity are tied up in other investments. Prepayment Risk - The risk that, with declining interest rates, fixed income securities with stated interests may have the principal paid earlier than expected, requiring the Fund to invest the proceeds at generally lower interest rates. U.S. Government Securities Risk - Although U.S. Government securities are considered to be among the safest investments, they are not guaranteed against price movements due to changing interest rates. Obligations issued by some U.S. Government agencies are backed by the U.S. Treasury, while others are backed solely by the ability of the agency to borrow from the U.S. Treasury or by the agency's own resources.
Risk, Lose Money	rr_RiskLoseMoney	Although the Fund seeks to maintain a constant price per share of $1.00, you may lose money by investing in the Fund.
Risk, Not Insured Depository Institution	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a bank deposit nor is it insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table, Heading	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance, Narrative	rr_PerformanceNarrativeTextBlock	As of January 31, 2012, the Fund had not commenced operations and did not have a performance history.
Performance, One Year or Less	rr_PerformanceOneYearOrLess	As of January 31, 2012, the Fund had not commenced operations and did not have a performance history.
SIMT Prime Obligation Fund (Prospectus Summary) | SIMT Prime Obligation Fund | Class A
Risk Return [Abstract]	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.06%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.71%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.77%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.33%)
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.44%	[2]
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	2013-01-31
Expense Example, With Redemption, 1 Year	rr_ExpenseExampleYear01	45
Expense Example, With Redemption, 3 Years	rr_ExpenseExampleYear03	213

[1] Other expenses are based on estimated amounts for the current fiscal year.

[2] SEI Investments Global Funds Services has contractually agreed to waive fees and to reimburse expenses in order to keep total operating expenses, exclusive of interest from borrowings, brokerage, commissions, taxes, trustee fees and extraordinary expenses not incurred in the ordinary course of the Fund's business and net of the Fund's distributor's fee waivers, from exceeding 0.44%. This fee waiver and reimbursement agreement shall remain in effect until January 31, 2013 and, unless earlier terminated, shall be automatically renewed for successive one year periods thereafter. The agreement may be amended or terminated only with the consent of the Board of Trustees.