Label

Element

Value

Common Stock Fund

Risk/Return:

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Supplement [Text Block]

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FMI Funds, Inc.

December 28, 2018

Supplement to the Statutory Prospectus dated January 31, 2018

Effective as of January 1, 2019, Fiduciary Management, Inc., the investment adviser to FMI Funds, Inc. has reduced the investment advisory fee for the FMI Large Cap Fund and the FMI Common Stock Fund.  To reflect these changes, the description of the management fees under the section “Management of the Funds” of the Statutory Prospectus, on page 20, is hereby supplemented as follows:

Effective as of January 1, 2019, the investment adviser is entitled to receive a fee for the FMI Large Cap Fund and the FMI Common Stock Fund based on the following annual percentages of each Fund’s average daily net assets:

• FMI Large Cap Fund: 0.65% of the assets from $0 - $2.5 billion; 0.60% of the assets from $2.5 - $5.0 billion; and 0.55% of the assets over $5.0 billion.

• FMI Common Stock Fund: 0.85% of the assets from $0 - $500 million; 0.80% of the assets from $500 million - $1.0 billion; and 0.75% of the assets over $1.0 billion.

FMI Common Stock Fund

Risk/Return [Heading]

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Common Stock Fund

Expense Narrative [Text Block]

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To reflect the reduced investment advisory fee, the “Annual Fund Operating Expenses” table and the “Example” under the section “Fees and Expenses of the Fund” of the Statutory Prospectus, on page 7, are hereby deleted and replaced in their entirety as set forth below:

Operating Expenses Caption [Text]

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

Expenses Restated to Reflect Current [Text]

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Management fees have been restated to reflect the implementation of reduced fees paid at various breakpoints in the Fund’s management fee, which became effective on January 1, 2019, as if the reduced breakpoints had been in effect during all of the 2017 fiscal year.

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 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 these periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same.

Expense Example by, Year, Caption [Text]

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

Expense Example Closing [Text Block]

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* * *

Please Read Carefully and Keep for Future Reference

Common Stock Fund | Common Stock Fund Investor Class

Risk/Return:

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Management Fees

rr_ManagementFeesOverAssets

0.82%

^[1]

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Shareholder Servicing Fees

rr_Component1OtherExpensesOverAssets

0.09%

^[2]

Remaining Other Expenses

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0.08%

Other Expenses

rr_OtherExpensesOverAssets

0.17%

Total Annual Fund Operating Expenses

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0.99%

Expense Example, with Redemption, 1 Year

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$ 101

Expense Example, with Redemption, 3 Years

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315

Expense Example, with Redemption, 5 Years

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547

Expense Example, with Redemption, 10 Years

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$ 1,213

Common Stock Fund | Common Stock Fund Institutional Class

Risk/Return:

rr_RiskReturnAbstract

Management Fees

rr_ManagementFeesOverAssets

0.82%

^[1]

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Shareholder Servicing Fees

rr_Component1OtherExpensesOverAssets

none

^[2]

Remaining Other Expenses

rr_Component3OtherExpensesOverAssets

0.08%

Other Expenses

rr_OtherExpensesOverAssets

0.08%

Total Annual Fund Operating Expenses

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0.90%

Expense Example, with Redemption, 1 Year

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$ 92

Expense Example, with Redemption, 3 Years

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287

Expense Example, with Redemption, 5 Years

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498

Expense Example, with Redemption, 10 Years

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$ 1,108

[1] Management fees have been restated to reflect the implementation of reduced fees paid at various breakpoints in the Fund's management fee, which became effective on January 1, 2019, as if the reduced breakpoints had been in effect during all of the 2017 fiscal year.

[2] Shareholder Servicing Fees have been annualized to reflect a full year of fees.