485BPOS

As filed with the United States Securities and Exchange Commission on December 27, 2012

1933 Act File No. 033-19862
1940 Act File No. 811-05460

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
Pre-Effective Amendment No.	o
Post-Effective Amendment No. 51	þ
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940
Amendment No. 55	þ

AIM TREASURER’S SERIES TRUST (INVESCO TREASURER’S SERIES TRUST)

(Exact Name of Registrant as Specified in Charter)

11 Greenway Plaza, Suite 1000, Houston, TX 77046
(Address of Principal Executive Offices)

Registrant’s Telephone Number, including Area Code: (713) 626-1919

John M. Zerr, Esquire
11 Greenway Plaza, Suite 1000, Houston, TX 77046
(Name and Address of Agent for Service)

Copies to:

Seba Kurian, Esquire	E. Carolan Berkley, Esquire
Invesco Advisers, Inc.	Stradley Ronon Stevens & Young
11 Greenway Plaza, Suite 1000	2005 Market Street, Suite 2600
Houston, Texas 77046	Philadelphia, Pennsylvania 19103-7018

Approximate Date of Proposed Public Offering: As soon as practicable after this post-effective amendment becomes effective.

It is proposed that this filing will become effective (check appropriate box)

þ immediately upon filing pursuant to paragraph (b)

o on [date], pursuant to paragraph (b)

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

o on (date ), pursuant to paragraph (a)(1)

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

o On (date), pursuant to paragraph (a)(2) of rule 485

If appropriate, check the following box:

o this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements for effectiveness of this Registration Statement pursuant to Rule 485(b) under the Securities Act of 1933 and has duly caused this Amendment to its Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the city of Houston, Texas on the 27th day of December, 2012.

Registrant:	AIM TREASURER’S SERIES TRUST
	(INVESCO TREASURER’S SERIES TRUST)
	By:	/s/ Karen Dunn Kelley Karen Dunn Kelley, President

     Pursuant to the requirements of the Securities Act of 1933, this Amendment to the Registration Statement has been signed below by the following persons in the capacities and on the dates indicated:

SIGNATURES	TITLE	DATE
/s/ Karen Dunn Kelley (Karen Dunn Kelley)	President  (Principal Executive Officer)	December 27, 2012
/s/ David C. Arch* (David C. Arch)	Trustee	December 27, 2012
/s/ Frank S. Bayley* (Frank S. Bayley)	Trustee	December 27, 2012
/s/ James T. Bunch* (James T. Bunch)	Trustee	December 27, 2012
/s/ Bruce L. Crockett* (Bruce L. Crockett)	Chair & Trustee	December 27, 2012
/s/ Rodney Dammeyer* (Rod Dammeyer)	Trustee	December 27, 2012
/s/ Albert R. Dowden* (Albert R. Dowden)	Trustee	December 27, 2012
/s/ Martin L. Flanagan* (Martin L. Flanagan)	Trustee	December 27, 2012
/s/ Jack M. Fields* (Jack M. Fields)	Trustee	December 27, 2012
/s/ Carl Frischling* (Carl Frischling)	Trustee	December 27, 2012
/s/ Prema Mathai-Davis* (Prema Mathai-Davis)	Trustee	December 27, 2012

SIGNATURES	TITLE	DATE
/s/ Larry Soll* (Larry Soll)	Trustee	December 27, 2012
/s/ Hugo F. Sonnenschein* (Hugo F. Sonnenschein)	Trustee	December 27, 2012
/s/ Raymond Stickel, Jr.* (Raymond Stickel, Jr.)	Trustee	December 27, 2012
/s/ Wayne W. Whalen* (Wayne W. Whalen)	Trustee	December 27, 2012
/s/ Sheri Morris (Sheri Morris)	Vice President & Treasurer (Principal Financial and Accounting Officer)	December 27, 2012

*By	/s/ Philip A. Taylor
	Philip A. Taylor Attorney-in-Fact

* Philip A. Taylor, pursuant to powers of attorney filed in Registrants Post-Effective Amendment No. 47 dated December 21, 2010.

Exhibit Index

XBRL Instance Document	Ex-101.ins
XBRL Taxonomy Extension Schema Document	Ex-101.sch
XBRL Taxonomy Extension Calculation Linkbase Document	Ex-101.cal
XBRL Taxonomy Extension Labels Linkbase	Ex-101.lab
XBRL Taxonomy Extension Presentation Linkbase Document	Ex-101.pre
XBRL Taxonomy Extension Definition Linkbase	Ex-101.def

XML

Institutional

Fund Summaries - PREMIER U.S. GOVERNMENT MONEY PORTFOLIO

Investment Objective(s)

The Fund’s investment objective is a high level of current income consistent with the preservation of capital and the maintenance of liquidity.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees	Institutional Premier U.S. Government Money Portfolio Institutional Class
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Institutional Premier U.S. Government Money Portfolio Institutional Class
Management Fees		0.25%
Distribution and/or Service (12b-1) Fees		none
Other Expenses		none
Total Annual Fund Operating Expenses		0.25%
Fee Waiver and/or Expense Reimbursement	[1]	0.07%
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		0.18%

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 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.

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

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Institutional Premier U.S. Government Money Portfolio Institutional Class	18	73	134	311

Principal Investment Strategies of the Fund

The Fund invests under normal circumstances at least 80% of its net assets (plus any borrowings for investment purposes) in (i) direct obligations of the U.S. Treasury, (ii) other securities issued or guaranteed as to principal and interest by the U.S. government or its agencies and instrumentalities (Agency Securities), and (iii) repurchase agreements secured by those obligations referenced in (i) and (ii) above. Agency Securities may be supported by (i) the full faith and credit of the U.S. Treasury; (ii) the right of the issuer to borrow from the U.S. Treasury; (iii) the discretionary authority of the U.S. government to purchase certain obligations of the agency or instrumentality; or (iv) the credit of the agency or instrumentality. At the present time, the fund has no current intention to invest in securities other than direct obligations of the U.S. Treasury, Agency Securities, and repurchase agreements secured by such obligations.

        The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.

        The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with SEC rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.

        In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.

        The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.

Principal Risks of Investing in the Fund

As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:

        Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.

        Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.

        Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.

        Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.

        Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.

        Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.

        Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.

        Repurchase Agreement Risk. If the seller of a repurchase agreement defaults or otherwise does not fulfill its obligations, the Fund may incur delays and losses arising from selling the underlying securities, enforcing its rights, or declining collateral value.

        U.S. Government Obligations Risk. The Fund may invest in obligations issued by U.S. Government agencies and instrumentalities that may receive varying levels of support from the government, which could affect the Fund’s ability to recover should they default.

Performance Information

The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.

Annual Total Returns

Institutional Class year-to-date (ended September 30, 2012): 0.02%
Best Quarter (ended September 30, 2007): 1.29%
Worst Quarter (ended June 30, 2011 through December 31, 2011): 0.00%

Average Annual Total Returns (for the periods ended December 31, 2011)

Average Annual Total Returns	1 Year	5 Years	Since Inception	Inception Date
Institutional Premier U.S. Government Money Portfolio Institutional Class	0.02%	1.52%	1.86%	Jun. 28, 2006

[1] Invesco Advisers, Inc. (Invesco or the Adviser) has contractually agreed, through at least December 31, 2013, to waive advisory fees equal to 0.07% of the average daily net assets of Premier U.S. Government Money Portfolio. Fee waivers have been restated to reflect this agreement. Unless the Board of Trustees and Invesco mutually agree to amend or continue the fee waiver agreement, it will terminate on December 31, 2013.

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Investor | Premier Tax-Exempt Portfolio

Fund Summaries - PREMIER TAX-EXEMPT PORTFOLIO

Investment Objective(s)

The Fund’s investment objective is to provide tax-exempt income consistent with preservation of capital and liquidity.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees	Investor Premier Tax-Exempt Portfolio Investor Class
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Investor Premier Tax-Exempt Portfolio Investor Class
Management Fees	0.25%
Distribution and/or Service (12b-1) Fees	none
Other Expenses	none
Total Annual Fund Operating Expenses	0.25%

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 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.

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

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Investor Premier Tax-Exempt Portfolio Investor Class	26	80	141	318

Principal Investment Strategies of the Fund

The Fund invests under normal circumstances at least 80% of its net assets (plus any borrowings for investment purposes) in securities that (1) pay interest that is excluded from gross income for federal income tax purposes, and (2) do not produce income that will be considered to be an item of preference for purposes of the alternative minimum tax.

        The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.

        The Fund invests only in high-quality U.S. dollar-denominated short-term debt obligations, including: (i) municipal securities; (ii) tax-exempt commercial paper; and (iii) cash equivalents. These securities may have credit and liquidity enhancements provided by banks, insurance companies or other financial institutions. Municipal securities include debt obligations of states, territories and possessions of the United States and the District of Columbia, their political subdivisions, agencies, instrumentalities, authorities thereof, and multi-state agencies, issued to obtain funds for various public purposes. Municipal lease obligations, synthetic municipal securities and certain types of industrial revenue bonds are treated as municipal securities.

        Other securities held by the fund may be structured with demand features which have the effect of shortening the security’s maturity.

        The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with SEC rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.

        The Fund may invest up to 20% of its total assets in money market instruments that may be subject to federal taxes, including Treasury securities, repurchase agreements, bankers’ acceptances, commercial paper, U.S. dollar-denominated foreign securities and master notes.

        The Fund may also invest in securities, whether or not considered foreign securities, which carry foreign credit exposure.

        In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.

        The portfolio structure is driven to some extent by the supply and availability of municipal obligations. The portfolio managers manage liquidity, for instance, by trading in daily and weekly variable-rate demand notes.

        The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.

Principal Risks of Investing in the Fund

As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:

        Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.

        Counterparty Risk. Counterparty risk is the risk that the other party to the contract will not fulfill its contractual obligations, which may cause losses or additional costs to the Fund.

        Credit Risk. The issuer of instruments in which the Fund invests may be unable to meet interest and/or principal payments, thereby causing its instruments to decrease in value and lowering the issuer’s credit rating.

        Foreign Credit Exposure Risk. U.S. dollar-denominated securities carrying foreign credit exposure may be affected by unfavorable political, economic or governmental developments that could affect payments of principal and interest.

        Foreign Securities Risk. The value of the Fund’s foreign investments may be adversely affected by political and social instability, changes in economic or taxation policies, difficulties when enforcing obligations, decreased liquidity, and increased volatility. Foreign companies may be subject to less regulation resulting in less publicly available information about the companies.

        Industry Focus Risk. To the extent the Fund invests in securities issued or guaranteed by companies in the banking and financial services industries, the Fund’s performance will depend on the overall condition of those industries, which may be affected by the following factors: the supply of short-term financing, changes in government regulation and interest rates, and the overall economy.

        Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.

        Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.

        Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.

        Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.

        Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.

        Municipal Securities Risk. The Fund may invest in municipal securities. Constitutional amendments, legislative enactments, executive orders, administrative regulations, voter initiatives, and the issuer’s regional economic conditions may affect the municipal security’s value, interest payments, repayment of principal and the Fund’s ability to sell it. Failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities.

        Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.

        Variable-Rate Demand Notes Risk. The absence of an active secondary market for certain variable and floating rate notes could make it difficult to dispose of the instruments, and a portfolio could suffer a loss if the issuer defaults during periods in which a portfolio is not entitled to exercise its demand rights.

Performance Information

The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.

Annual Total Returns

Investor Class year-to-date (ended September 30, 2012): 0.02%
Best Quarter (ended June 30, 2007 and September 30, 2007): 0.89%
Worst Quarter (ended June 30, 2011 through December 31, 2011): 0.01%

Average Annual Total Returns (for the periods ended December 31, 2011)

Average Annual Total Returns	1 Year	5 Years	10 Years	Inception Date
Investor Premier Tax-Exempt Portfolio Investor Class	0.05%	1.27%	1.53%	Apr. 27, 1988

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	AIM TREASURERS SERIES TRUST (INVESCO TREASURER'S SERIES TRUST)
Prospectus Date	rr_ProspectusDate	Dec. 21, 2012
Institutional | Premier U.S. Government Money Portfolio
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summaries - PREMIER U.S. GOVERNMENT MONEY PORTFOLIO
Objective [Heading]	rr_ObjectiveHeading	Investment Objective(s)
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is a high level of current income consistent with the preservation of capital and the maintenance of liquidity.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
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, 2013
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 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.         Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests under normal circumstances at least 80% of its net assets (plus any borrowings for investment purposes) in (i) direct obligations of the U.S. Treasury, (ii) other securities issued or guaranteed as to principal and interest by the U.S. government or its agencies and instrumentalities (Agency Securities), and (iii) repurchase agreements secured by those obligations referenced in (i) and (ii) above. Agency Securities may be supported by (i) the full faith and credit of the U.S. Treasury; (ii) the right of the issuer to borrow from the U.S. Treasury; (iii) the discretionary authority of the U.S. government to purchase certain obligations of the agency or instrumentality; or (iv) the credit of the agency or instrumentality. At the present time, the fund has no current intention to invest in securities other than direct obligations of the U.S. Treasury, Agency Securities, and repurchase agreements secured by such obligations.         The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.         The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with SEC rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.         In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.         The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.
Risk [Heading]	rr_RiskHeading	Principal Risks of Investing in the Fund
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:         Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.         Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.         Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.         Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.         Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.         Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.         Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.         Repurchase Agreement Risk. If the seller of a repurchase agreement defaults or otherwise does not fulfill its obligations, the Fund may incur delays and losses arising from selling the underlying securities, enforcing its rights, or declining collateral value.         U.S. Government Obligations Risk. The Fund may invest in obligations issued by U.S. Government agencies and instrumentalities that may receive varying levels of support from the government, which could affect the Fund’s ability to recover should they default.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any mutual fund investment, loss of money is a risk of investing.
Risk Money Market Fund [Text]	rr_RiskMoneyMarketFund	Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.invesco.com/us
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Institutional Class year-to-date (ended September 30, 2012): 0.02% Best Quarter (ended September 30, 2007): 1.29% Worst Quarter (ended June 30, 2011 through December 31, 2011): 0.00%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
Institutional | Premier U.S. Government Money Portfolio | Institutional Class
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	rr_MaximumDeferredSalesChargeOverOther	none
Management Fees	rr_ManagementFeesOverAssets	0.25%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.25%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.07%	[1]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.18%
1 Year	rr_ExpenseExampleYear01	18
3 Years	rr_ExpenseExampleYear03	73
5 Years	rr_ExpenseExampleYear05	134
10 Years	rr_ExpenseExampleYear10	311
2007	rr_AnnualReturn2007	5.09%
2008	rr_AnnualReturn2008	2.29%
2009	rr_AnnualReturn2009	0.28%
2010	rr_AnnualReturn2010	0.03%
2011	rr_AnnualReturn2011	0.02%
Year to Date Return, Label	rr_YearToDateReturnLabel	Institutional Class year-to-date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	0.02%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2007
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	1.29%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	0.00%
1 Year	rr_AverageAnnualReturnYear01	0.02%
5 Years	rr_AverageAnnualReturnYear05	1.52%
Since Inception	rr_AverageAnnualReturnSinceInception	1.86%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jun. 28, 2006

[1] Invesco Advisers, Inc. (Invesco or the Adviser) has contractually agreed, through at least December 31, 2013, to waive advisory fees equal to 0.07% of the average daily net assets of Premier U.S. Government Money Portfolio. Fee waivers have been restated to reflect this agreement. Unless the Board of Trustees and Invesco mutually agree to amend or continue the fee waiver agreement, it will terminate on December 31, 2013.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	AIM TREASURERS SERIES TRUST (INVESCO TREASURER'S SERIES TRUST)
Prospectus Date	rr_ProspectusDate	Dec. 21, 2012
Institutional | Premier Portfolio
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summaries - PREMIER PORTFOLIO
Objective [Heading]	rr_ObjectiveHeading	Investment Objective(s)
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is to provide current income consistent with preservation of capital and liquidity.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
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, 2013
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 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.          Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests primarily in high-quality U.S. dollar-denominated short-term debt obligations, including: (i) securities issued by the U.S. Government or its agencies; (ii) bankers’ acceptances, certificates of deposit, and time deposits from U.S. and foreign banks; (iii) repurchase agreements; (iv) commercial paper; (v) municipal securities; and (vi) master notes.          The Fund may engage in repurchase agreement transactions that are collateralized by cash or government securities. In addition, it may engage in repurchase agreement transactions that are collateralized by non government securities such as equity securities and securities that are rated investment grade and below investment grade by nationally recognized statistical rating organizations or unrated securities of comparable quality.          The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.          The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with the Security and Exchange Commission (SEC) rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.          The Fund invests from time to time in U.S. dollar-denominated foreign securities. The Fund may also invest in securities, whether or not considered foreign securities, which carry foreign credit exposure.          In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.          The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.
Risk [Heading]	rr_RiskHeading	Principal Risks of Investing in the Fund
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:          Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.          Counterparty Risk. Counterparty risk is the risk that the other party to the contract will not fulfill its contractual obligations, which may cause losses or additional costs to the Fund.          Credit Risk. The issuer of instruments in which the Fund invests may be unable to meet interest and/or principal payments, thereby causing its instruments to decrease in value and lowering the issuer’s credit rating.          Foreign Credit Exposure Risk. U.S. dollar-denominated securities carrying foreign credit exposure may be affected by unfavorable political, economic or governmental developments that could affect payments of principal and interest.          Foreign Securities Risk. The value of the Fund’s foreign investments may be adversely affected by political and social instability, changes in economic or taxation policies, difficulties when enforcing obligations, decreased liquidity, and increased volatility. Foreign companies may be subject to less regulation resulting in less publicly available information about the companies.          Industry Focus Risk. To the extent the Fund invests in securities issued or guaranteed by companies in the banking and financial services industries, the Fund’s performance will depend on the overall condition of those industries, which may be affected by the following factors: the supply of short-term financing, changes in government regulation and interest rates, and the overall economy.          Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.          Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.          Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.          Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.          Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.          Municipal Securities Risk. The Fund may invest in municipal securities. Constitutional amendments, legislative enactments, executive orders, administrative regulations, voter initiatives, and the issuer’s regional economic conditions may affect the municipal security’s value, interest payments, repayment of principal and the Fund’s ability to sell it. Failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities.          Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.          Repurchase Agreement Risk. If the seller of a repurchase agreement defaults or otherwise does not fulfill its obligations, the Fund may incur delays and losses arising from selling the underlying securities, enforcing its rights, or declining collateral value. These risks are magnified to the extent that a repurchase agreement is secured by securities other than cash or U.S. Government securities.          U.S. Government Obligations Risk. The Fund may invest in obligations issued by U.S. Government agencies and instrumentalities that may receive varying levels of support from the government, which could affect the Fund’s ability to recover should they default.          Variable-Rate Demand Notes Risk. The absence of an active secondary market for certain variable and floating rate notes could make it difficult to dispose of the instruments, and a portfolio could suffer a loss if the issuer defaults during periods in which a portfolio is not entitled to exercise its demand rights.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any mutual fund investment, loss of money is a risk of investing.
Risk Money Market Fund [Text]	rr_RiskMoneyMarketFund	Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.invesco.com/us
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Institutional Class year-to-date (ended September 30, 2012): 0.09% Best Quarter (ended September 30, 2007): 1.33% Worst Quarter (ended March 31, 2010 and September 30, 2011): 0.01%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
Institutional | Premier Portfolio | Institutional Class
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	rr_MaximumDeferredSalesChargeOverOther	none
Management Fees	rr_ManagementFeesOverAssets	0.25%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.25%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.07%	[1]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.18%
1 Year	rr_ExpenseExampleYear01	18
3 Years	rr_ExpenseExampleYear03	73
5 Years	rr_ExpenseExampleYear05	134
10 Years	rr_ExpenseExampleYear10	311
2006	rr_AnnualReturn2006	5.04%
2007	rr_AnnualReturn2007	5.27%
2008	rr_AnnualReturn2008	2.89%
2009	rr_AnnualReturn2009	0.46%
2010	rr_AnnualReturn2010	0.09%
2011	rr_AnnualReturn2011	0.07%
Year to Date Return, Label	rr_YearToDateReturnLabel	Institutional Class year-to-date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	0.09%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2007
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	1.33%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	0.01%
1 Year	rr_AverageAnnualReturnYear01	0.07%
5 Years	rr_AverageAnnualReturnYear05	1.74%
Since Inception	rr_AverageAnnualReturnSinceInception	2.41%
Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 25, 2005

[1] Invesco Advisers, Inc. (Invesco or the Adviser) has contractually agreed, through at least December 31, 2013, to waive advisory fees equal to 0.07% of the average daily net assets of Premier Portfolio. Fee waivers have been restated to reflect this agreement. Unless the Board of Trustees and Invesco mutually agree to amend or continue the fee waiver agreement, it will terminate on December 31, 2013.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	AIM TREASURERS SERIES TRUST (INVESCO TREASURER'S SERIES TRUST)
Prospectus Date	rr_ProspectusDate	Dec. 21, 2012
Document Creation Date	dei_DocumentCreationDate	Dec. 18, 2012

XML

Institutional | Premier Tax-Exempt Portfolio

Fund Summaries - PREMIER TAX-EXEMPT PORTFOLIO

Investment Objective(s)

The Fund’s investment objective is to provide tax-exempt income consistent with preservation of capital and liquidity.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees	Institutional Premier Tax-Exempt Portfolio Institutional Class
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Institutional Premier Tax-Exempt Portfolio Institutional Class
Management Fees	0.25%
Distribution and/or Service (12b-1) Fees	none
Other Expenses	none
Total Annual Fund Operating Expenses	0.25%

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 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.

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

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Institutional Premier Tax-Exempt Portfolio Institutional Class	26	80	141	318

Principal Investment Strategies of the Fund

The Fund invests under normal circumstances at least 80% of its net assets (plus any borrowings for investment purposes) in securities that (1) pay interest that is excluded from gross income for federal income tax purposes, and (2) do not produce income that will be considered to be an item of preference for purposes of the alternative minimum tax.

        The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.

        The Fund invests only in high-quality U.S. dollar-denominated short-term debt obligations, including: (i) municipal securities; (ii) tax-exempt commercial paper; and (iii) cash equivalents. These securities may have credit and liquidity enhancements provided by banks, insurance companies or other financial institutions. Municipal securities include debt obligations of states, territories and possessions of the United States and the District of Columbia, their political subdivisions, agencies, instrumentalities, authorities thereof, and multi-state agencies, issued to obtain funds for various public purposes. Municipal lease obligations, synthetic municipal securities and certain types of industrial revenue bonds are treated as municipal securities.

        Other securities held by the fund may be structured with demand features which have the effect of shortening the security’s maturity.

        The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with SEC rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.

        The Fund may invest up to 20% of its total assets in money market instruments that may be subject to federal taxes, including Treasury securities, repurchase agreements, bankers’ acceptances, commercial paper, U.S. dollar-denominated foreign securities and master notes.

        The Fund may also invest in securities, whether or not considered foreign securities, which carry foreign credit exposure.

        In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.

        The portfolio structure is driven to some extent by the supply and availability of municipal obligations. The portfolio managers manage liquidity, for instance, by trading in daily and weekly variable-rate demand notes.

        The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.

Principal Risks of Investing in the Fund

As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:

        Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.

        Counterparty Risk. Counterparty risk is the risk that the other party to the contract will not fulfill its contractual obligations, which may cause losses or additional costs to the Fund.

        Credit Risk. The issuer of instruments in which the Fund invests may be unable to meet interest and/or principal payments, thereby causing its instruments to decrease in value and lowering the issuer’s credit rating.

        Foreign Credit Exposure Risk. U.S. dollar-denominated securities carrying foreign credit exposure may be affected by unfavorable political, economic or governmental developments that could affect payments of principal and interest.

        Foreign Securities Risk. The value of the Fund’s foreign investments may be adversely affected by political and social instability, changes in economic or taxation policies, difficulties when enforcing obligations, decreased liquidity, and increased volatility. Foreign companies may be subject to less regulation resulting in less publicly available information about the companies.

        Industry Focus Risk. To the extent the Fund invests in securities issued or guaranteed by companies in the banking and financial services industries, the Fund’s performance will depend on the overall condition of those industries, which may be affected by the following factors: the supply of short-term financing, changes in government regulation and interest rates, and the overall economy.

        Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.

        Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.

        Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.

        Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.

        Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.

        Municipal Securities Risk. The Fund may invest in municipal securities. Constitutional amendments, legislative enactments, executive orders, administrative regulations, voter initiatives, and the issuer’s regional economic conditions may affect the municipal security’s value, interest payments, repayment of principal and the Fund’s ability to sell it. Failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities.

        Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.

        Variable-Rate Demand Notes Risk. The absence of an active secondary market for certain variable and floating rate notes could make it difficult to dispose of the instruments, and a portfolio could suffer a loss if the issuer defaults during periods in which a portfolio is not entitled to exercise its demand rights.

Performance Information

The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.

Annual Total Returns

Institutional Class year-to-date (ended September 30, 2012): 0.02%
Best Quarter (ended June 30, 2007 and September 30, 2007): 0.89%
Worst Quarter (ended December 31, 2011): 0.00%

Average Annual Total Returns (for the periods ended December 31, 2011)

Average Annual Total Returns	1 Year	5 Years	Since Inception	Inception Date
Institutional Premier Tax-Exempt Portfolio Institutional Class	0.05%	1.27%	1.71%	Feb. 25, 2005

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	AIM TREASURERS SERIES TRUST (INVESCO TREASURER'S SERIES TRUST)
Prospectus Date	rr_ProspectusDate	Dec. 21, 2012
Investor | Premier Portfolio
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summaries - PREMIER PORTFOLIO
Objective [Heading]	rr_ObjectiveHeading	Investment Objective(s)
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is to provide current income consistent with preservation of capital and liquidity.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
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, 2013
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 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.         Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests primarily in high-quality U.S. dollar-denominated short-term debt obligations, including: (i) securities issued by the U.S. Government or its agencies; (ii) bankers’ acceptances, certificates of deposit, and time deposits from U.S. and foreign banks; (iii) repurchase agreements; (iv) commercial paper; (v) municipal securities; and (vi) master notes.          The Fund may engage in repurchase agreement transactions that are collateralized by cash or government securities. In addition, it may engage in repurchase agreement transactions that are collateralized by non government securities such as equity securities and securities that are rated investment grade and below investment grade by nationally recognized statistical rating organizations or unrated securities of comparable quality.         The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.          The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with the Security and Exchange Commission (SEC) rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.         The Fund invests from time to time in U.S. dollar-denominated foreign securities. The Fund may also invest in securities, whether or not considered foreign securities, which carry foreign credit exposure.          In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.          The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.
Risk [Heading]	rr_RiskHeading	Principal Risks of Investing in the Fund
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:         Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.         Counterparty Risk. Counterparty risk is the risk that the other party to the contract will not fulfill its contractual obligations, which may cause losses or additional costs to the Fund.         Credit Risk. The issuer of instruments in which the Fund invests may be unable to meet interest and/or principal payments, thereby causing its instruments to decrease in value and lowering the issuer’s credit rating.         Foreign Credit Exposure Risk. U.S. dollar-denominated securities carrying foreign credit exposure may be affected by unfavorable political, economic or governmental developments that could affect payments of principal and interest.         Foreign Securities Risk. The value of the Fund’s foreign investments may be adversely affected by political and social instability, changes in economic or taxation policies, difficulties when enforcing obligations, decreased liquidity, and increased volatility. Foreign companies may be subject to less regulation resulting in less publicly available information about the companies.         Industry Focus Risk. To the extent the Fund invests in securities issued or guaranteed by companies in the banking and financial services industries, the Fund’s performance will depend on the overall condition of those industries, which may be affected by the following factors: the supply of short-term financing, changes in government regulation and interest rates, and the overall economy.          Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.         Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.          Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.         Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.         Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.        Municipal Securities Risk. The Fund may invest in municipal securities. Constitutional amendments, legislative enactments, executive orders, administrative regulations, voter initiatives, and the issuer’s regional economic conditions may affect the municipal security’s value, interest payments, repayment of principal and the Fund’s ability to sell it. Failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities.         Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.         Repurchase Agreement Risk. If the seller of a repurchase agreement defaults or otherwise does not fulfill its obligations, the Fund may incur delays and losses arising from selling the underlying securities, enforcing its rights, or declining collateral value. These risks are magnified to the extent that a repurchase agreement is secured by securities other than cash or U.S. Government securities.         U.S. Government Obligations Risk. The Fund may invest in obligations issued by U.S. Government agencies and instrumentalities that may receive varying levels of support from the government, which could affect the Fund’s ability to recover should they default.        Variable-Rate Demand Notes Risk. The absence of an active secondary market for certain variable and floating rate notes could make it difficult to dispose of the instruments, and a portfolio could suffer a loss if the issuer defaults during periods in which a portfolio is not entitled to exercise its demand rights.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any mutual fund investment, loss of money is a risk of investing.
Risk Money Market Fund [Text]	rr_RiskMoneyMarketFund	Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.invesco.com/us
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Investor Class year-to-date (ended September 30, 2012): 0.09% Best Quarter (ended September 30, 2007): 1.33% Worst Quarter (ended March 31, 2010 and September 30, 2011): 0.01%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
Investor | Premier Portfolio | Investor Class
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	rr_MaximumDeferredSalesChargeOverOther	none
Management Fees	rr_ManagementFeesOverAssets	0.25%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.25%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.07%	[1]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.18%
1 Year	rr_ExpenseExampleYear01	18
3 Years	rr_ExpenseExampleYear03	73
5 Years	rr_ExpenseExampleYear05	134
10 Years	rr_ExpenseExampleYear10	311
2002	rr_AnnualReturn2002	1.55%
2003	rr_AnnualReturn2003	1.03%
2004	rr_AnnualReturn2004	1.27%
2005	rr_AnnualReturn2005	3.17%
2006	rr_AnnualReturn2006	5.04%
2007	rr_AnnualReturn2007	5.27%
2008	rr_AnnualReturn2008	2.90%
2009	rr_AnnualReturn2009	0.46%
2010	rr_AnnualReturn2010	0.09%
2011	rr_AnnualReturn2011	0.08%
Year to Date Return, Label	rr_YearToDateReturnLabel	Investor Class year-to-date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	0.09%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2007
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	1.33%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	0.01%
1 Year	rr_AverageAnnualReturnYear01	0.08%
5 Years	rr_AverageAnnualReturnYear05	1.74%
10 Years	rr_AverageAnnualReturnYear10	2.07%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 26, 1988

[1] Invesco Advisers, Inc. (Invesco or the Adviser) has contractually agreed, through at least December 31, 2013, to waive advisory fees equal to 0.07% of the average daily net assets of Premier Portfolio. Fee waivers have been restated to reflect this agreement. Unless the Board of Trustees and Invesco mutually agree to amend or continue the fee waiver agreement, it will terminate on December 31, 2013.

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Investor | Premier Portfolio

Fund Summaries - PREMIER PORTFOLIO

Investment Objective(s)

The Fund’s investment objective is to provide current income consistent with preservation of capital and liquidity.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees	Investor Premier Portfolio Investor Class
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Investor Premier Portfolio Investor Class
Management Fees		0.25%
Distribution and/or Service (12b-1) Fees		none
Other Expenses		none
Total Annual Fund Operating Expenses		0.25%
Fee Waiver and/or Expense Reimbursement	[1]	0.07%
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		0.18%

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 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.

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

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Investor Premier Portfolio Investor Class	18	73	134	311

Principal Investment Strategies of the Fund

The Fund invests primarily in high-quality U.S. dollar-denominated short-term debt obligations, including: (i) securities issued by the U.S. Government or its agencies; (ii) bankers’ acceptances, certificates of deposit, and time deposits from U.S. and foreign banks; (iii) repurchase agreements; (iv) commercial paper; (v) municipal securities; and (vi) master notes.

         The Fund may engage in repurchase agreement transactions that are collateralized by cash or government securities. In addition, it may engage in repurchase agreement transactions that are collateralized by non government securities such as equity securities and securities that are rated investment grade and below investment grade by nationally recognized statistical rating organizations or unrated securities of comparable quality.

        The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.

         The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with the Security and Exchange Commission (SEC) rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.

        The Fund invests from time to time in U.S. dollar-denominated foreign securities. The Fund may also invest in securities, whether or not considered foreign securities, which carry foreign credit exposure.

         In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.

         The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.

Principal Risks of Investing in the Fund

As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:

        Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.

        Counterparty Risk. Counterparty risk is the risk that the other party to the contract will not fulfill its contractual obligations, which may cause losses or additional costs to the Fund.

        Credit Risk. The issuer of instruments in which the Fund invests may be unable to meet interest and/or principal payments, thereby causing its instruments to decrease in value and lowering the issuer’s credit rating.

        Foreign Credit Exposure Risk. U.S. dollar-denominated securities carrying foreign credit exposure may be affected by unfavorable political, economic or governmental developments that could affect payments of principal and interest.

        Foreign Securities Risk. The value of the Fund’s foreign investments may be adversely affected by political and social instability, changes in economic or taxation policies, difficulties when enforcing obligations, decreased liquidity, and increased volatility. Foreign companies may be subject to less regulation resulting in less publicly available information about the companies.

        Industry Focus Risk. To the extent the Fund invests in securities issued or guaranteed by companies in the banking and financial services industries, the Fund’s performance will depend on the overall condition of those industries, which may be affected by the following factors: the supply of short-term financing, changes in government regulation and interest rates, and the overall economy.

         Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.

        Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.

         Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.

        Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.

        Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.

       Municipal Securities Risk. The Fund may invest in municipal securities. Constitutional amendments, legislative enactments, executive orders, administrative regulations, voter initiatives, and the issuer’s regional economic conditions may affect the municipal security’s value, interest payments, repayment of principal and the Fund’s ability to sell it. Failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities.

        Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.

        Repurchase Agreement Risk. If the seller of a repurchase agreement defaults or otherwise does not fulfill its obligations, the Fund may incur delays and losses arising from selling the underlying securities, enforcing its rights, or declining collateral value. These risks are magnified to the extent that a repurchase agreement is secured by securities other than cash or U.S. Government securities.

        U.S. Government Obligations Risk. The Fund may invest in obligations issued by U.S. Government agencies and instrumentalities that may receive varying levels of support from the government, which could affect the Fund’s ability to recover should they default.

       Variable-Rate Demand Notes Risk. The absence of an active secondary market for certain variable and floating rate notes could make it difficult to dispose of the instruments, and a portfolio could suffer a loss if the issuer defaults during periods in which a portfolio is not entitled to exercise its demand rights.

Performance Information

The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.

Annual Total Returns

Investor Class year-to-date (ended September 30, 2012): 0.09%
Best Quarter (ended September 30, 2007): 1.33%
Worst Quarter (ended March 31, 2010 and September 30, 2011): 0.01%

Average Annual Total Returns (for the periods ended December 31, 2011)

Average Annual Total Returns	1 Year	5 Years	10 Years	Inception Date
Investor Premier Portfolio Investor Class	0.08%	1.74%	2.07%	Apr. 26, 1988

[1] Invesco Advisers, Inc. (Invesco or the Adviser) has contractually agreed, through at least December 31, 2013, to waive advisory fees equal to 0.07% of the average daily net assets of Premier Portfolio. Fee waivers have been restated to reflect this agreement. Unless the Board of Trustees and Invesco mutually agree to amend or continue the fee waiver agreement, it will terminate on December 31, 2013.

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Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	AIM TREASURERS SERIES TRUST (INVESCO TREASURER'S SERIES TRUST)
Prospectus Date	rr_ProspectusDate	Dec. 21, 2012
Investor | Premier U.S. Government Money Portfolio
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summaries - PREMIER U.S. GOVERNMENT MONEY PORTFOLIO
Objective [Heading]	rr_ObjectiveHeading	Investment Objective(s)
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is a high level of current income consistent with the preservation of capital and the maintenance of liquidity.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
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, 2013
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 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.         Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests under normal circumstances at least 80% of its net assets (plus any borrowings for investment purposes) in (i) direct obligations of the U.S. Treasury, (ii) other securities issued or guaranteed as to principal and interest by the U.S. government or its agencies and instrumentalities (Agency Securities), and (iii) repurchase agreements secured by those obligations referenced in (i) and (ii) above. Agency Securities may be supported by (i) the full faith and credit of the U.S. Treasury; (ii) the right of the issuer to borrow from the U.S. Treasury; (iii) the discretionary authority of the U.S. government to purchase certain obligations of the agency or instrumentality; or (iv) the credit of the agency or instrumentality. At the present time, the fund has no current intention to invest in securities other than direct obligations of the U.S. Treasury, Agency Securities, and repurchase agreements secured by such obligations.         The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.         The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with SEC rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.         In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.         The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.
Risk [Heading]	rr_RiskHeading	Principal Risks of Investing in the Fund
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:         Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.         Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.         Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.         Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.         Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.         Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.         Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.         Repurchase Agreement Risk. If the seller of a repurchase agreement defaults or otherwise does not fulfill its obligations, the Fund may incur delays and losses arising from selling the underlying securities, enforcing its rights, or declining collateral value.         U.S. Government Obligations Risk. The Fund may invest in obligations issued by U.S. Government agencies and instrumentalities that may receive varying levels of support from the government, which could affect the Fund’s ability to recover should they default.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any mutual fund investment, loss of money is a risk of investing.
Risk Money Market Fund [Text]	rr_RiskMoneyMarketFund	Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.invesco.com/us
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Investor Class year-to-date (ended September 30, 2012): 0.02% Best Quarter (ended December 31, 2006): 1.30% Worst Quarter (ended March 31, 2010 through December 31, 2011): 0.01%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
Investor | Premier U.S. Government Money Portfolio | Investor Class
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	rr_MaximumDeferredSalesChargeOverOther	none
Management Fees	rr_ManagementFeesOverAssets	0.25%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.25%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.07%	[1]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.18%
1 Year	rr_ExpenseExampleYear01	18
3 Years	rr_ExpenseExampleYear03	73
5 Years	rr_ExpenseExampleYear05	134
10 Years	rr_ExpenseExampleYear10	311
2002	rr_AnnualReturn2002	0.90%
2003	rr_AnnualReturn2003	0.37%
2004	rr_AnnualReturn2004	0.56%
2005	rr_AnnualReturn2005	3.00%
2006	rr_AnnualReturn2006	4.92%
2007	rr_AnnualReturn2007	5.09%
2008	rr_AnnualReturn2008	2.29%
2009	rr_AnnualReturn2009	0.28%
2010	rr_AnnualReturn2010	0.03%
2011	rr_AnnualReturn2011	0.02%
Year to Date Return, Label	rr_YearToDateReturnLabel	Investor Class year-to-date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	0.02%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Dec. 31, 2006
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	1.30%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	0.01%
1 Year	rr_AverageAnnualReturnYear01	0.02%
5 Years	rr_AverageAnnualReturnYear05	1.52%
10 Years	rr_AverageAnnualReturnYear10	1.73%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 26, 1991

[1] Invesco Advisers, Inc. (Invesco or the Adviser) has contractually agreed, through at least December 31, 2013, to waive advisory fees equal to 0.07% of the average daily net assets of Premier U.S. Government Money Portfolio. Fee waivers have been restated to reflect this agreement. Unless the Board of Trustees and Invesco mutually agree to amend or continue the fee waiver agreement, it will terminate on December 31, 2013.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	AIM TREASURERS SERIES TRUST (INVESCO TREASURER'S SERIES TRUST)
Prospectus Date	rr_ProspectusDate	Dec. 21, 2012
Institutional | Premier Tax-Exempt Portfolio
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summaries - PREMIER TAX-EXEMPT PORTFOLIO
Objective [Heading]	rr_ObjectiveHeading	Investment Objective(s)
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is to provide tax-exempt income consistent with preservation of capital and liquidity.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
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)
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 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.         Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests under normal circumstances at least 80% of its net assets (plus any borrowings for investment purposes) in securities that (1) pay interest that is excluded from gross income for federal income tax purposes, and (2) do not produce income that will be considered to be an item of preference for purposes of the alternative minimum tax.         The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.         The Fund invests only in high-quality U.S. dollar-denominated short-term debt obligations, including: (i) municipal securities; (ii) tax-exempt commercial paper; and (iii) cash equivalents. These securities may have credit and liquidity enhancements provided by banks, insurance companies or other financial institutions. Municipal securities include debt obligations of states, territories and possessions of the United States and the District of Columbia, their political subdivisions, agencies, instrumentalities, authorities thereof, and multi-state agencies, issued to obtain funds for various public purposes. Municipal lease obligations, synthetic municipal securities and certain types of industrial revenue bonds are treated as municipal securities.         Other securities held by the fund may be structured with demand features which have the effect of shortening the security’s maturity.         The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with SEC rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.         The Fund may invest up to 20% of its total assets in money market instruments that may be subject to federal taxes, including Treasury securities, repurchase agreements, bankers’ acceptances, commercial paper, U.S. dollar-denominated foreign securities and master notes.         The Fund may also invest in securities, whether or not considered foreign securities, which carry foreign credit exposure.         In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.         The portfolio structure is driven to some extent by the supply and availability of municipal obligations. The portfolio managers manage liquidity, for instance, by trading in daily and weekly variable-rate demand notes.         The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.
Risk [Heading]	rr_RiskHeading	Principal Risks of Investing in the Fund
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:         Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.         Counterparty Risk. Counterparty risk is the risk that the other party to the contract will not fulfill its contractual obligations, which may cause losses or additional costs to the Fund.         Credit Risk. The issuer of instruments in which the Fund invests may be unable to meet interest and/or principal payments, thereby causing its instruments to decrease in value and lowering the issuer’s credit rating.         Foreign Credit Exposure Risk. U.S. dollar-denominated securities carrying foreign credit exposure may be affected by unfavorable political, economic or governmental developments that could affect payments of principal and interest.         Foreign Securities Risk. The value of the Fund’s foreign investments may be adversely affected by political and social instability, changes in economic or taxation policies, difficulties when enforcing obligations, decreased liquidity, and increased volatility. Foreign companies may be subject to less regulation resulting in less publicly available information about the companies.         Industry Focus Risk. To the extent the Fund invests in securities issued or guaranteed by companies in the banking and financial services industries, the Fund’s performance will depend on the overall condition of those industries, which may be affected by the following factors: the supply of short-term financing, changes in government regulation and interest rates, and the overall economy.         Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.         Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.         Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.         Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.         Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.         Municipal Securities Risk. The Fund may invest in municipal securities. Constitutional amendments, legislative enactments, executive orders, administrative regulations, voter initiatives, and the issuer’s regional economic conditions may affect the municipal security’s value, interest payments, repayment of principal and the Fund’s ability to sell it. Failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities.         Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.         Variable-Rate Demand Notes Risk. The absence of an active secondary market for certain variable and floating rate notes could make it difficult to dispose of the instruments, and a portfolio could suffer a loss if the issuer defaults during periods in which a portfolio is not entitled to exercise its demand rights.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any mutual fund investment, loss of money is a risk of investing.
Risk Money Market Fund [Text]	rr_RiskMoneyMarketFund	Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.invesco.com/us
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Institutional Class year-to-date (ended September 30, 2012): 0.02% Best Quarter (ended June 30, 2007 and September 30, 2007): 0.89% Worst Quarter (ended December 31, 2011): 0.00%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
Institutional | Premier Tax-Exempt Portfolio | Institutional Class
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	rr_MaximumDeferredSalesChargeOverOther	none
Management Fees	rr_ManagementFeesOverAssets	0.25%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.25%
1 Year	rr_ExpenseExampleYear01	26
3 Years	rr_ExpenseExampleYear03	80
5 Years	rr_ExpenseExampleYear05	141
10 Years	rr_ExpenseExampleYear10	318
2006	rr_AnnualReturn2006	3.32%
2007	rr_AnnualReturn2007	3.51%
2008	rr_AnnualReturn2008	2.33%
2009	rr_AnnualReturn2009	0.41%
2010	rr_AnnualReturn2010	0.11%
2011	rr_AnnualReturn2011	0.05%
Year to Date Return, Label	rr_YearToDateReturnLabel	Institutional Class year-to-date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	0.02%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2007
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	0.89%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	0.00%
1 Year	rr_AverageAnnualReturnYear01	0.05%
5 Years	rr_AverageAnnualReturnYear05	1.27%
Since Inception	rr_AverageAnnualReturnSinceInception	1.71%
Inception Date	rr_AverageAnnualReturnInceptionDate	Feb. 25, 2005

XML

Document and Entity Information	12 Months Ended
	Dec. 21, 2012
Risk/Return:
Document Type	485BPOS
Document Period End Date	Aug. 31, 2012
Registrant Name	AIM TREASURERS SERIES TRUST (INVESCO TREASURER'S SERIES TRUST)
Central Index Key	0000828806
Amendment Flag	false
Document Creation Date	Dec. 18, 2012
Document Effective Date	Dec. 21, 2012
Prospectus Date	Dec. 21, 2012

XML

Institutional | Premier Portfolio

Fund Summaries - PREMIER PORTFOLIO

Investment Objective(s)

The Fund’s investment objective is to provide current income consistent with preservation of capital and liquidity.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees	Institutional Premier Portfolio Institutional Class
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Institutional Premier Portfolio Institutional Class
Management Fees		0.25%
Distribution and/or Service (12b-1) Fees		none
Other Expenses		none
Total Annual Fund Operating Expenses		0.25%
Fee Waiver and/or Expense Reimbursement	[1]	0.07%
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		0.18%

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 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.

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

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Institutional Premier Portfolio Institutional Class	18	73	134	311

Principal Investment Strategies of the Fund

The Fund invests primarily in high-quality U.S. dollar-denominated short-term debt obligations, including: (i) securities issued by the U.S. Government or its agencies; (ii) bankers’ acceptances, certificates of deposit, and time deposits from U.S. and foreign banks; (iii) repurchase agreements; (iv) commercial paper; (v) municipal securities; and (vi) master notes.

         The Fund may engage in repurchase agreement transactions that are collateralized by cash or government securities. In addition, it may engage in repurchase agreement transactions that are collateralized by non government securities such as equity securities and securities that are rated investment grade and below investment grade by nationally recognized statistical rating organizations or unrated securities of comparable quality.

         The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.

         The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with the Security and Exchange Commission (SEC) rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.

         The Fund invests from time to time in U.S. dollar-denominated foreign securities. The Fund may also invest in securities, whether or not considered foreign securities, which carry foreign credit exposure.

         In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.

         The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.

Principal Risks of Investing in the Fund

As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:

         Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.

         Counterparty Risk. Counterparty risk is the risk that the other party to the contract will not fulfill its contractual obligations, which may cause losses or additional costs to the Fund.

         Credit Risk. The issuer of instruments in which the Fund invests may be unable to meet interest and/or principal payments, thereby causing its instruments to decrease in value and lowering the issuer’s credit rating.

         Foreign Credit Exposure Risk. U.S. dollar-denominated securities carrying foreign credit exposure may be affected by unfavorable political, economic or governmental developments that could affect payments of principal and interest.

         Foreign Securities Risk. The value of the Fund’s foreign investments may be adversely affected by political and social instability, changes in economic or taxation policies, difficulties when enforcing obligations, decreased liquidity, and increased volatility. Foreign companies may be subject to less regulation resulting in less publicly available information about the companies.

         Industry Focus Risk. To the extent the Fund invests in securities issued or guaranteed by companies in the banking and financial services industries, the Fund’s performance will depend on the overall condition of those industries, which may be affected by the following factors: the supply of short-term financing, changes in government regulation and interest rates, and the overall economy.

         Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.

         Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.

         Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.

         Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.

         Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.

         Municipal Securities Risk. The Fund may invest in municipal securities. Constitutional amendments, legislative enactments, executive orders, administrative regulations, voter initiatives, and the issuer’s regional economic conditions may affect the municipal security’s value, interest payments, repayment of principal and the Fund’s ability to sell it. Failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities.

         Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.

         Repurchase Agreement Risk. If the seller of a repurchase agreement defaults or otherwise does not fulfill its obligations, the Fund may incur delays and losses arising from selling the underlying securities, enforcing its rights, or declining collateral value. These risks are magnified to the extent that a repurchase agreement is secured by securities other than cash or U.S. Government securities.

         U.S. Government Obligations Risk. The Fund may invest in obligations issued by U.S. Government agencies and instrumentalities that may receive varying levels of support from the government, which could affect the Fund’s ability to recover should they default.

         Variable-Rate Demand Notes Risk. The absence of an active secondary market for certain variable and floating rate notes could make it difficult to dispose of the instruments, and a portfolio could suffer a loss if the issuer defaults during periods in which a portfolio is not entitled to exercise its demand rights.

Performance Information

The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.

Annual Total Returns

Institutional Class year-to-date (ended September 30, 2012): 0.09%
Best Quarter (ended September 30, 2007): 1.33%
Worst Quarter (ended March 31, 2010 and September 30, 2011): 0.01%

Average Annual Total Returns (for the periods ended December 31, 2011)

Average Annual Total Returns	1 Year	5 Years	Since Inception	Inception Date
Institutional Premier Portfolio Institutional Class	0.07%	1.74%	2.41%	Feb. 25, 2005

[1] Invesco Advisers, Inc. (Invesco or the Adviser) has contractually agreed, through at least December 31, 2013, to waive advisory fees equal to 0.07% of the average daily net assets of Premier Portfolio. Fee waivers have been restated to reflect this agreement. Unless the Board of Trustees and Invesco mutually agree to amend or continue the fee waiver agreement, it will terminate on December 31, 2013.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	AIM TREASURERS SERIES TRUST (INVESCO TREASURER'S SERIES TRUST)
Prospectus Date	rr_ProspectusDate	Dec. 21, 2012
Investor | Premier Tax-Exempt Portfolio
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summaries - PREMIER TAX-EXEMPT PORTFOLIO
Objective [Heading]	rr_ObjectiveHeading	Investment Objective(s)
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is to provide tax-exempt income consistent with preservation of capital and liquidity.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
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)
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 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.         Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests under normal circumstances at least 80% of its net assets (plus any borrowings for investment purposes) in securities that (1) pay interest that is excluded from gross income for federal income tax purposes, and (2) do not produce income that will be considered to be an item of preference for purposes of the alternative minimum tax.         The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.         The Fund invests only in high-quality U.S. dollar-denominated short-term debt obligations, including: (i) municipal securities; (ii) tax-exempt commercial paper; and (iii) cash equivalents. These securities may have credit and liquidity enhancements provided by banks, insurance companies or other financial institutions. Municipal securities include debt obligations of states, territories and possessions of the United States and the District of Columbia, their political subdivisions, agencies, instrumentalities, authorities thereof, and multi-state agencies, issued to obtain funds for various public purposes. Municipal lease obligations, synthetic municipal securities and certain types of industrial revenue bonds are treated as municipal securities.         Other securities held by the fund may be structured with demand features which have the effect of shortening the security’s maturity.         The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with SEC rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.         The Fund may invest up to 20% of its total assets in money market instruments that may be subject to federal taxes, including Treasury securities, repurchase agreements, bankers’ acceptances, commercial paper, U.S. dollar-denominated foreign securities and master notes.         The Fund may also invest in securities, whether or not considered foreign securities, which carry foreign credit exposure.         In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.         The portfolio structure is driven to some extent by the supply and availability of municipal obligations. The portfolio managers manage liquidity, for instance, by trading in daily and weekly variable-rate demand notes.         The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.
Risk [Heading]	rr_RiskHeading	Principal Risks of Investing in the Fund
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:         Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.         Counterparty Risk. Counterparty risk is the risk that the other party to the contract will not fulfill its contractual obligations, which may cause losses or additional costs to the Fund.         Credit Risk. The issuer of instruments in which the Fund invests may be unable to meet interest and/or principal payments, thereby causing its instruments to decrease in value and lowering the issuer’s credit rating.         Foreign Credit Exposure Risk. U.S. dollar-denominated securities carrying foreign credit exposure may be affected by unfavorable political, economic or governmental developments that could affect payments of principal and interest.         Foreign Securities Risk. The value of the Fund’s foreign investments may be adversely affected by political and social instability, changes in economic or taxation policies, difficulties when enforcing obligations, decreased liquidity, and increased volatility. Foreign companies may be subject to less regulation resulting in less publicly available information about the companies.         Industry Focus Risk. To the extent the Fund invests in securities issued or guaranteed by companies in the banking and financial services industries, the Fund’s performance will depend on the overall condition of those industries, which may be affected by the following factors: the supply of short-term financing, changes in government regulation and interest rates, and the overall economy.         Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.         Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.         Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.         Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.         Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.         Municipal Securities Risk. The Fund may invest in municipal securities. Constitutional amendments, legislative enactments, executive orders, administrative regulations, voter initiatives, and the issuer’s regional economic conditions may affect the municipal security’s value, interest payments, repayment of principal and the Fund’s ability to sell it. Failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities.         Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.         Variable-Rate Demand Notes Risk. The absence of an active secondary market for certain variable and floating rate notes could make it difficult to dispose of the instruments, and a portfolio could suffer a loss if the issuer defaults during periods in which a portfolio is not entitled to exercise its demand rights.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with any mutual fund investment, loss of money is a risk of investing.
Risk Money Market Fund [Text]	rr_RiskMoneyMarketFund	Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.invesco.com/us
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Investor Class year-to-date (ended September 30, 2012): 0.02% Best Quarter (ended June 30, 2007 and September 30, 2007): 0.89% Worst Quarter (ended June 30, 2011 through December 31, 2011): 0.01%
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (for the periods ended December 31, 2011)
Investor | Premier Tax-Exempt Portfolio | Investor Class
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	rr_MaximumDeferredSalesChargeOverOther	none
Management Fees	rr_ManagementFeesOverAssets	0.25%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.25%
1 Year	rr_ExpenseExampleYear01	26
3 Years	rr_ExpenseExampleYear03	80
5 Years	rr_ExpenseExampleYear05	141
10 Years	rr_ExpenseExampleYear10	318
2002	rr_AnnualReturn2002	1.29%
2003	rr_AnnualReturn2003	0.97%
2004	rr_AnnualReturn2004	1.08%
2005	rr_AnnualReturn2005	2.29%
2006	rr_AnnualReturn2006	3.32%
2007	rr_AnnualReturn2007	3.51%
2008	rr_AnnualReturn2008	2.33%
2009	rr_AnnualReturn2009	0.41%
2010	rr_AnnualReturn2010	0.11%
2011	rr_AnnualReturn2011	0.05%
Year to Date Return, Label	rr_YearToDateReturnLabel	Investor Class year-to-date
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	0.02%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2007
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	0.89%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	0.01%
1 Year	rr_AverageAnnualReturnYear01	0.05%
5 Years	rr_AverageAnnualReturnYear05	1.27%
10 Years	rr_AverageAnnualReturnYear10	1.53%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 27, 1988

XML

Investor

Fund Summaries - PREMIER U.S. GOVERNMENT MONEY PORTFOLIO

Investment Objective(s)

The Fund’s investment objective is a high level of current income consistent with the preservation of capital and the maintenance of liquidity.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees	Investor Premier U.S. Government Money Portfolio Investor Class
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	none
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, whichever is less)	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Investor Premier U.S. Government Money Portfolio Investor Class
Management Fees		0.25%
Distribution and/or Service (12b-1) Fees		none
Other Expenses		none
Total Annual Fund Operating Expenses		0.25%
Fee Waiver and/or Expense Reimbursement	[1]	0.07%
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement		0.18%

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 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.

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

Expense Example (USD $)	1 Year	3 Years	5 Years	10 Years
Investor Premier U.S. Government Money Portfolio Investor Class	18	73	134	311

Principal Investment Strategies of the Fund

The Fund invests under normal circumstances at least 80% of its net assets (plus any borrowings for investment purposes) in (i) direct obligations of the U.S. Treasury, (ii) other securities issued or guaranteed as to principal and interest by the U.S. government or its agencies and instrumentalities (Agency Securities), and (iii) repurchase agreements secured by those obligations referenced in (i) and (ii) above. Agency Securities may be supported by (i) the full faith and credit of the U.S. Treasury; (ii) the right of the issuer to borrow from the U.S. Treasury; (iii) the discretionary authority of the U.S. government to purchase certain obligations of the agency or instrumentality; or (iv) the credit of the agency or instrumentality. At the present time, the fund has no current intention to invest in securities other than direct obligations of the U.S. Treasury, Agency Securities, and repurchase agreements secured by such obligations.

        The Fund will limit investments to those securities that are First Tier Securities (defined below) at the time of purchase.

        The Fund is a money market fund that seeks to maintain a stable price of $1.00 per share by using the amortized cost method to value portfolio securities and rounding the share value to the nearest cent. The Fund invests in conformity with SEC rules and regulation requirements for money market funds for the quality, maturity, diversification and liquidity of investments. The Fund invests only in U.S. dollar-denominated securities maturing within 397 days of the date of purchase, with certain exceptions permitted by applicable regulations. The Fund maintains a dollar-weighted average portfolio maturity of no more than 60 days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a-7 under the Investment Company Act of 1940 of no more than 120 days. Each investment must be determined to present minimal credit risks by the Fund’s Adviser pursuant to guidelines approved by the Fund’s Board of Trustees, and must be an “Eligible Security” as defined under applicable regulations. First Tier Securities generally means Eligible Securities rated within the highest short-term rating category, an unrated security of comparable quality as determined by the Adviser under the supervision of the Board of Trustees, U.S. Government Securities as defined by applicable regulations, and securities issued by other registered money market funds.

        In selecting securities for the Fund’s portfolio, the portfolio managers focus on securities that offer safety, liquidity, and a competitive yield. The Adviser conducts a credit analysis of each potential issuer prior to the purchase of its securities.

        The portfolio managers normally hold portfolio securities to maturity, but may sell a security when they deem it advisable, such as when market or credit factors materially change.

Principal Risks of Investing in the Fund

As with any mutual fund investment, loss of money is a risk of investing. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The risks associated with an investment in the Fund can increase during times of significant market volatility. The principal risks of investing in the Fund are:

        Cash/Cash Equivalents Risk. Holding cash or cash equivalents may negatively affect performance.

        Interest Rate Risk. Interest rate risk refers to the risk that bond prices generally fall as interest rates rise; conversely, bond prices generally rise as interest rates fall. Specific bonds differ in their sensitivity to changes in interest rates depending on their individual characteristics, including duration.

        Liquidity Risk. The Fund may hold illiquid securities that it may be unable to sell at the preferred time or price and could lose its entire investment in such securities.

        Management Risk. The investment techniques and risk analysis used by the Fund’s portfolio managers may not produce the desired results.

        Market Risk. The prices of and the income generated by the Fund’s securities may decline in response to, among other things, investor sentiment, general economic and market conditions, regional or global instability, and interest rate fluctuations.

        Money Market Fund Risk. Although the Fund seeks to preserve the value of your investment at $1.00 per share, you may lose money by investing in the Fund. The share price of money market funds can fall below the $1.00 share price. You should not rely on or expect the Fund’s adviser or its affiliates to enter into support agreements or take other actions to maintain the Fund’s $1.00 share price. The credit quality of the Fund’s holdings can change rapidly in certain markets, and the default of a single holding could have an adverse impact on the Fund’s share price. The Fund’s share price can also be negatively affected during periods of high redemption pressures and/or illiquid markets. Further regulation could impact the way the Fund is managed, possibly negatively impacting its return. Additionally, the Fund’s yield will vary as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in other securities.

        Reinvestment Risk. Reinvestment risk is the risk that a bond’s cash flows (coupon income and principal repayment) will be reinvested at an interest rate below that on the original bond.

        Repurchase Agreement Risk. If the seller of a repurchase agreement defaults or otherwise does not fulfill its obligations, the Fund may incur delays and losses arising from selling the underlying securities, enforcing its rights, or declining collateral value.

        U.S. Government Obligations Risk. The Fund may invest in obligations issued by U.S. Government agencies and instrumentalities that may receive varying levels of support from the government, which could affect the Fund’s ability to recover should they default.

Performance Information

The bar chart and performance table provide an indication of the risks of investing in the Fund. The bar chart shows changes in the performance of the Fund from year to year as of December 31. The Fund’s past performance (before and after taxes) is not necessarily an indication of its future performance. Updated performance information is available on the Fund’s website at www.invesco.com/us.

Annual Total Returns

Investor Class year-to-date (ended September 30, 2012): 0.02%
Best Quarter (ended December 31, 2006): 1.30%
Worst Quarter (ended March 31, 2010 through December 31, 2011): 0.01%

Average Annual Total Returns (for the periods ended December 31, 2011)

Average Annual Total Returns	1 Year	5 Years	10 Years	Inception Date
Investor Premier U.S. Government Money Portfolio Investor Class	0.02%	1.52%	1.73%	Apr. 26, 1991

[1] Invesco Advisers, Inc. (Invesco or the Adviser) has contractually agreed, through at least December 31, 2013, to waive advisory fees equal to 0.07% of the average daily net assets of Premier U.S. Government Money Portfolio. Fee waivers have been restated to reflect this agreement. Unless the Board of Trustees and Invesco mutually agree to amend or continue the fee waiver agreement, it will terminate on December 31, 2013.