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Sale of Assets of Diamond Hill's High Yield-Focused Fund (Details)		3 Months Ended	9 Months Ended
	Feb. 02, 2021 USD ($) payment	Sep. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of high yield-focused advisory contracts			$ 9,000,000	$ 0
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Acquired Funds
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of high yield-focused advisory contracts		$ 9,000,000
Number of additional payments | payment	2
Additional consideration	$ 13,000,000
Additional consideration, term	1 year

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