Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	BMO FUNDS, INC.
Prospectus Date	rr_ProspectusDate	Dec. 29, 2016
BMO Disciplined International Equity Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	BMO Disciplined International Equity Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective:
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	To provide capital appreciation.
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. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Class A shares of certain BMO Funds. More information about these and other discounts is available from your financial professional and under “How to Buy Shares – Purchase of Class A Shares – Class A Shares – Sales Charge” on page 124 of this Prospectus and under “How to Buy Shares – Class A Shares – Waivers and Reductions of Sales Charges” beginning on page 125 of this Prospectus and “How to Buy Shares” beginning on page B-38 of the Fund’s Statement of Additional Information.
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, 2017
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund incurs transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal period ended August 31, 2016, the Fund’s portfolio turnover rate (not annualized) was 64% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	64.00%
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	The Maximum Deferred Sales Charge on Class A shares is applied only to purchases of $1,000,000 or more that are redeemed within 18 months of purchase.
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Class A shares of certain BMO Funds.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	$ 50,000
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	Other Expenses for the Class R3 and Class R6 shares are based on estimated amounts for the current fiscal year.
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 funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, whether you redeem all of your shares at the end of those periods or not. 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 December 31, 2017. Although your actual costs and returns may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests at least 80% of its assets in equity securities of companies located in countries outside of the United States. The Fund invests primarily in companies that are located in the countries included, at the time of purchase, in the MSCI EAFE Index, which includes developed countries outside of North America. However, the Fund may invest up to 20% of its net assets in companies located in countries not represented in this index, including emerging market countries. Equity securities in which the Fund may invest include common stock, preferred stock, depositary receipts, rights, warrants, and exchange-traded funds (ETFs). The Fund also may invest in convertible securities (fixed income securities convertible into shares of common or preferred stock). In determining where a company is located, the Adviser primarily relies on the country where the company is incorporated, but also may consider the country where the company's revenues are derived and the primary market listing for the class of shares to be purchased. The Fund may invest in companies across all market capitalizations and may at times focus its investments in one or more sectors. The Fund's Adviser focuses on companies that it believes are fundamentally strong, have attractive valuations, possess growing investor interest, and may outperform the overall equity market. Using a unique approach which combines the use of proprietary analytical tools and the qualitative judgments of the investment team, the Adviser selects equity securities that it believes will provide higher returns than the MSCI EAFE Index, its benchmark index. As part of this process, the Adviser considers numerous factors including (but not limited to) valuation, earnings quality, earnings growth potential, and earnings and price momentum. The Adviser invests in those securities it believes will provide a better return relative to their risk than other securities. The Adviser may sell a security for numerous reasons, including if a company's fundamentals deteriorate or the Adviser believes a company's fundamentals will deteriorate, if another security appears to provide the potential for a better return relative to its risk, if the Adviser believes the security is no longer attractively valued, or if the Adviser believes the security will no longer help the Fund achieve its investment objective. The Adviser also may sell a security to manage the size of a holding or sector weighting or to fund redemptions. The Fund may invest in forward foreign currency exchange contracts, a type of derivative instrument, for purposes of hedging its exposure to non-U.S. currencies. From time to time, the Fund maintains a portion of its assets in cash. The Fund may increase its cash holdings in response to market conditions or in the event attractive investment opportunities are not available.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The Fund cannot assure that it will achieve its investment objective. 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. The net asset value of the Fund will vary and you could lose money by investing in the Fund. In addition, the Fund is subject to the following risks. Common Stock Risks. Common stocks are susceptible to general stock market fluctuations and to volatile increases and decreases in value as market confidence in, and perceptions of, their issuers change. Holders of common stocks are generally subject to greater risk than holders of preferred stocks and debt obligations of the same issuer because common stockholders generally have inferior rights to receive payments from issuers in comparison with the rights of preferred stockholders, bondholders, and other creditors. Company Size Risks. Generally, the smaller the market capitalization of a company, the fewer the number of shares traded daily, the less liquid its stock and the more volatile its price. Companies with smaller market capitalizations also tend to have unproven track records, a limited product or service base, and limited access to capital. These factors also increase risks and make these companies more likely to fail than companies with larger market capitalizations. Convertible Security Risks. Convertible securities are fixed income securities that the Fund has the option to exchange for equity securities at a specified conversion price. Consequently, the value of the convertible security may be exposed to the stock market risk of the underlying stock, or may be exposed to the interest rate or credit risk of the issuer. Because both interest rate and market movements can influence its value, a convertible security is usually not as sensitive to interest rate changes as a similar fixed-income security, nor is it as sensitive to changes in share price as its underlying stock. Convertible securities also are subject to credit risks that affect debt securities in general. Currency Risks. To the extent that the Fund invests directly in foreign (non-U.S.) currencies or in securities denominated in, or that trade in, foreign (non-U.S.) currencies, it is subject to the risk that those currencies will decline in value relative to the U.S. dollar or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency being hedged. Emerging Markets Risks. Investments in emerging markets can involve risks in addition to, and greater than, those generally associated with investing in more developed foreign markets, which may make emerging market securities more volatile and potentially less liquid than securities issued in more developed markets. Exchange-Traded Funds Risks. By investing in an ETF, a risk exists that the value of the underlying securities of the ETF may decrease. In addition, the market price of ETF shares may trade at a discount to their net asset value or an active trading market for ETF shares may not develop or be maintained. ETFs in which the Fund invests typically will not be able to replicate exactly the performance of the indices they track. The Fund also will bear its proportionate share of the ETF's fees (including management and advisory fees) and expenses. Foreign Securities Risks. Investing in foreign securities may involve additional risks, including currency-rate fluctuations, political and economic instability, differences in financial reporting standards, less-strict regulation of the securities markets, and possible imposition of foreign withholding taxes. Furthermore, the Fund may incur higher costs and expenses when making foreign investments, which will affect the Fund's total return. Forward Foreign Currency Exchange Contracts Risks. Forward foreign currency exchange contracts are subject to currency risks. A forward foreign currency exchange contract also may result in losses in the event of a default or bankruptcy of the counterparty. Forward foreign currency exchange contracts may limit potential gain from a positive change in the relationship between the U.S. dollar and foreign currencies. Management Risks. The Adviser's judgments about the attractiveness, value, and potential appreciation of the Fund's investments may prove to be incorrect. Accordingly, no guarantee exists that the investment techniques used by the Fund's managers will produce the desired results. Sector Risks. Companies with similar characteristics, such as those within similar industries, may be grouped together in broad categories called sectors. To the extent the Fund invests its assets in a particular sector, the Fund's performance may be more susceptible to any economic, business, or other developments that generally affect that sector. Stock Market Risks. The Fund is subject to fluctuations in the stock market, which has periods of increasing and decreasing values. Stocks are more volatile than debt securities. The value of equity securities purchased by the Fund may decline if the financial condition of the companies in which the Fund invests declines or if overall market and economic conditions deteriorate. If the value of the Fund's investments goes down, you may lose money. U.S. and international markets have experienced significant volatility in recent years, which may increase the risks of investing in the securities held by the Fund. Policy changes by the U.S. government and/or Federal Reserve, such as raising interest rates, also could cause increased volatility in financial markets and higher levels of shareholder redemptions, which could have a negative impact on the Fund. Adverse market events also may lead to increased shareholder redemptions, which could cause the Fund to experience a loss or difficulty in selling investments to meet such redemptions.
Risk Lose Money [Text]	rr_RiskLoseMoney	The net asset value of the Fund will vary and you could lose money by investing in the Fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	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]	rr_BarChartAndPerformanceTableHeading	Fund Performance
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	Performance information is not included because the Fund does not have one full calendar year of performance as of the date of this Prospectus.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	Performance information is not included because the Fund does not have one full calendar year of performance as of the date of this Prospectus.
BMO Disciplined International Equity Fund | Class I
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 shares redeemed within 18 months of purchase)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Redemption Fee (as a percentage of amount redeemed, for shares held less than 30 days)	rr_RedemptionFeeOverRedemption	2.00%
Management Fees	rr_ManagementFeesOverAssets	0.60%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.60%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.20%
Fee Waiver and Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.30%)	[3]
Total Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	rr_NetExpensesOverAssets	0.90%	[3]
1 Year	rr_ExpenseExampleYear01	$ 92
3 Years	rr_ExpenseExampleYear03	351
5 Years	rr_ExpenseExampleYear05	631
10 Years	rr_ExpenseExampleYear10	1,428
1 Year	rr_ExpenseExampleNoRedemptionYear01	92
3 Years	rr_ExpenseExampleNoRedemptionYear03	351
5 Years	rr_ExpenseExampleNoRedemptionYear05	631
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 1,428
BMO Disciplined International Equity Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	5.00%
Maximum Deferred Sales Charge (Load) (as a percentage of shares redeemed within 18 months of purchase)	rr_MaximumDeferredSalesChargeOverOther	1.00%	[1]
Redemption Fee (as a percentage of amount redeemed, for shares held less than 30 days)	rr_RedemptionFeeOverRedemption	2.00%
Management Fees	rr_ManagementFeesOverAssets	0.60%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.60%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.45%
Fee Waiver and Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.30%)	[3]
Total Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	rr_NetExpensesOverAssets	1.15%	[3]
1 Year	rr_ExpenseExampleYear01	$ 611
3 Years	rr_ExpenseExampleYear03	908
5 Years	rr_ExpenseExampleYear05	1,225
10 Years	rr_ExpenseExampleYear10	2,124
1 Year	rr_ExpenseExampleNoRedemptionYear01	611
3 Years	rr_ExpenseExampleNoRedemptionYear03	908
5 Years	rr_ExpenseExampleNoRedemptionYear05	1,225
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 2,124
BMO Disciplined International Equity Fund | Class R3
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 shares redeemed within 18 months of purchase)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Redemption Fee (as a percentage of amount redeemed, for shares held less than 30 days)	rr_RedemptionFeeOverRedemption	2.00%
Management Fees	rr_ManagementFeesOverAssets	0.60%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.50%
Other Expenses	rr_OtherExpensesOverAssets	0.60%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.70%
Fee Waiver and Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.30%)	[3]
Total Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	rr_NetExpensesOverAssets	1.40%	[3]
1 Year	rr_ExpenseExampleYear01	$ 143
3 Years	rr_ExpenseExampleYear03	506
5 Years	rr_ExpenseExampleYear05	895
10 Years	rr_ExpenseExampleYear10	1,984
1 Year	rr_ExpenseExampleNoRedemptionYear01	143
3 Years	rr_ExpenseExampleNoRedemptionYear03	506
5 Years	rr_ExpenseExampleNoRedemptionYear05	895
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 1,984
BMO Disciplined International Equity Fund | Class R6
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 shares redeemed within 18 months of purchase)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Redemption Fee (as a percentage of amount redeemed, for shares held less than 30 days)	rr_RedemptionFeeOverRedemption	2.00%
Management Fees	rr_ManagementFeesOverAssets	0.60%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.45%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.05%
Fee Waiver and Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.30%)	[3]
Total Annual Fund Operating Expenses After Fee Waiver and Expense Reimbursement	rr_NetExpensesOverAssets	0.75%	[3]
1 Year	rr_ExpenseExampleYear01	$ 77
3 Years	rr_ExpenseExampleYear03	304
5 Years	rr_ExpenseExampleYear05	550
10 Years	rr_ExpenseExampleYear10	1,255
1 Year	rr_ExpenseExampleNoRedemptionYear01	77
3 Years	rr_ExpenseExampleNoRedemptionYear03	304
5 Years	rr_ExpenseExampleNoRedemptionYear05	550
10 Years	rr_ExpenseExampleNoRedemptionYear10	$ 1,255

[1] The Maximum Deferred Sales Charge on Class A shares is applied only to purchases of $1,000,000 or more that are redeemed within 18 months of purchase.

[2] Other Expenses for the Class R3 and Class R6 shares are based on estimated amounts for the current fiscal year.

[3] BMO Asset Management Corp. (Adviser) has agreed to waive or reduce its investment advisory fee and reimburse expenses to the extent necessary to prevent 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 0.90% for Class I, 1.15% for Class A, 1.40% for Class R3, and 0.75% for Class R6 through December 31, 2017. This expense limitation agreement may not be terminated prior to December 31, 2017 without the consent of the Fund’s Board of Directors, unless terminated due to the termination of the investment advisory agreement.