The expense information in the fee table has been restated to reflect that effective September 1, 2011, the Fund entered into a new transfer agency agreement

Expense Example [Heading]

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Example

Expense Example Narrative [Text Block]

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This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other 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 are as shown in the table and remain the same. The costs in the one-year example and for the first year of the three-, five-, and ten-year examples reflect the Adviser's agreement to waive fees and reimburse expenses through July 6, 2013. Although your actual costs and returns may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading]

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Principal Investment Strategies

Strategy Narrative [Text Block]

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The Fund invests its assets in high quality, short-term money market instruments and repurchase agreements. The Fund invests at least 80% of its assets in obligations issued and/or guaranteed by the U.S. government or by its agencies or instrumentalities, and in repurchase agreements secured by such obligations. The securities in which the Fund invests must be rated in one of the two highest short-term rating categories by one or more nationally recognized statistical rating organizations or be determined by the Adviser to be of comparable quality to securities having such ratings. The Adviser uses a "bottom-up" approach, which evaluates debt securities against the context of broader market factors such as the cyclical trend in interest rates, the shape of the yield curve and debt security supply factors.

The Fund invests in the securities of U.S. government-sponsored entities that are not backed by the full faith and credit of the U.S. government, but are supported through federal loans or other benefits, including the Federal Home Loan Banks (FHLBs), Federal National Mortgage Association (Fannie Mae) and Federal Home Loan Mortgage Corporation (Freddie Mac). The Fund also may invest in the securities of U.S. government-sponsored entities that are supported by the full faith and credit of the U.S. government, such as the Government National Mortgage Association (Ginnie Mae). Finally, the Fund may invest in the securities of governmental entities that have no explicit financial support from the U.S. government, but are regarded as having implied support because the U.S. government sponsors their activities, including the Farm Credit Administration and the Financing Corporation.

Risk [Heading]

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Principal Risks

Risk Narrative [Text Block]

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An investment in the Fund is not a deposit of BMO Harris Bank N.A. or any of its affiliates and is not insured or guaranteed by the FDIC or any other government agency. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it is possible to lose money by investing in the Fund. In addition, the Fund is subject to the following risks.

Interest Rate Risks. Prices of fixed income securities rise and fall in response to changes in the interest rate paid by similar securities. Generally, when interest rates rise, prices of fixed income securities fall. Interest rate changes have a greater effect on the price of fixed income securities with longer maturities.

Credit Risks. Credit risk is the possibility that an issuer or counterparty will default on a security or repurchase agreement by failing to pay interest or principal when due. If an issuer defaults, the Fund may lose money. Lower credit ratings correspond to higher credit risk.

Call Risks. If the securities in which the Fund invests are redeemed by the issuer before maturity (or "called"), the Fund may have to reinvest the proceeds in securities that pay a lower interest rate, which may decrease the Fund's yield. This will most likely happen when interest rates are declining.

Liquidity Risks. Liquidity risk refers to the possibility that the Fund may not be able to sell or buy a security or close out an investment contract at a favorable price or time. Consequently, the Fund may have to accept a lower price to sell a security, sell other securities to raise cash or give up an investment opportunity, any of which could have a negative effect on the Fund's performance. Infrequent trading of securities also may lead to an increase in their price volatility.

Government Obligations Risks. No assurance can be given that the U.S. government will provide financial support to U.S. government-sponsored agencies or instrumentalities where it is not obligated to do so by law. As a result, there is risk that these entities will default on a financial obligation.

Management Risks. The Adviser's judgments about the attractiveness, value and potential appreciation of the Fund's investments may prove to be incorrect. Accordingly, there is no guarantee that the investment techniques used by the Fund's manager will produce the desired results.

Risk Lose Money [Text]

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Although the Fund seeks to preserve the value of your investment at $1.00 per share, it is possible to lose money by investing in the Fund.

Risk Money Market Fund [Text]

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Risk Not Insured Depository Institution [Text]

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An investment in the Fund is not a deposit of BMO Harris Bank N.A. or any of its affiliates and is not insured or guaranteed by the FDIC or any other government agency.

Bar Chart and Performance Table [Heading]

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Fund Performance

Performance Narrative [Text Block]

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The bar chart and table show the historical performance of the Fund's shares and provide some indication of the risks of investing in the Fund. The bar chart shows how the Fund's total returns have varied from year to year, while the table compares the Fund's average annual total returns to the returns of an average of money funds with similar objectives and an index of funds with similar investment objectives. Please keep in mind that past performance does not represent how the Fund will perform in the future. Investors may obtain the Fund's current 7-Day Net Yield or updated performance information at www.bmofundsus.com.

Performance Information Illustrates Variability of Returns [Text]

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The bar chart shows how the Fund's total returns have varied from year to year, while the table compares the Fund's average annual total returns to the returns of an average of money funds with similar objectives and an index of funds with similar investment objectives.

Performance Availability Website Address [Text]

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www.bmofundsus.com

Performance Past Does Not Indicate Future [Text]

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Please keep in mind that past performance does not represent how the Fund will perform in the future.

Bar Chart [Heading]

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Class Y—Annual Total Returns (calendar years 2005-2010)

Bar Chart Closing [Text Block]

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The return for the Class Y shares of the Fund from January 1, 2011 through September 30, 2011 was 0.01%.

During the periods shown in the bar chart for the Fund:


	Quarter Ended		Returns
Best quarter		12/31/2006		1.24	%
Worst quarter		3/31/2010		0.00	%

7-Day Net Yield as of December 31, 2010 was 0.01%.

Performance Table Heading

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Average Annual Total Returns through 12/31/10

Performance Table Narrative

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The iMoneyNet Government Money Market Index (IMNGMMI) is an average of money funds with investment objectives similar to that of the Fund.

The Lipper U.S. Government Money Market Funds Index (LUSGMMFI) is an average of the 30 largest mutual funds in this Lipper category.

Money Market Seven Day Yield, Caption [Text]

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7-Day Net Yield as of December 31, 2010

Money Market Seven Day Yield

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0.01%

BMO Government Money Market Fund | IMNGMMI (reflects deduction of fees and no deduction for sales charges or taxes)

Risk/Return:

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1 Year

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0.02%

5 Year

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2.00%

Since Commencement of Operations

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1.95%

BMO Government Money Market Fund | LUSGMMFI (reflects deduction of fees and no deduction for sales charges or taxes)

Risk/Return:

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1 Year

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0.02%

5 Year

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2.16%

Since Commencement of Operations

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2.10%

[1]

The expense information in the fee table has been restated to reflect that effective September 1, 2011, the Fund entered into a new transfer agency agreement.

[2]

M&I Investment Management Corp. (Adviser) has agreed to waive or reduce its investment advisory fee and reimburse expenses to the extent necessary to prevent class total annual operating expenses (excluding interest, taxes, brokerage commissions, other investment-related costs and extraordinary expenses, such as litigation and other expenses not incurred in the ordinary course of the Fund's business and Acquired Fund Fees and Expenses) from exceeding 0.45% for Class Y and 0.20% for Class I through July 6, 2013. The Adviser may not terminate this arrangement prior to July 6, 2013 unless the investment advisory agreement is terminated.