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Business and Organization (Notes) | 12 Months Ended
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Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract] |
Business and Organization | Business and OrganizationDiamond Hill Investment Group, Inc. (the “Company”), an Ohio corporation, derives its consolidated revenues and net income from investment advisory and fund administration services.

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- Definition The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -URI http://asc.fasb.org/topic&trid=2122149 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -URI http://asc.fasb.org/topic&trid=2197479 + Details
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