XML 47 R33.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Investment Portfolio - Summary of Cash and Cash Equivalent Investments, Excluding Money Market Funds (Details) - USD ($) | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Summary of market value of investments |  |
Total Investment Portfolio | $ 52,490,820 | $ 45,427,456
Corporate Investments [Member] |  |
Summary of market value of investments |  |
Total Investment Portfolio | 44,529,408 | 39,748,692
Corporate Investments [Member] | Diamond Hill Mid Cap Fund |  |
Summary of market value of investments |  |
Total Investment Portfolio | 10,749,860 | 10,729,930
Corporate Investments [Member] | Diamond Hill Research Opportunities Fund |  |
Summary of market value of investments |  |
Total Investment Portfolio | 10,306,395 | 13,143,281
Corporate Investments [Member] | Diamond Hill Financial Long-Short Fund |  |
Summary of market value of investments |  |
Total Investment Portfolio | 967,721 | 1,222,892
Corporate Investments [Member] | Diamond Hill Valuation-Weighted 500 ETF |  |
Summary of market value of investments |  |
Total Investment Portfolio | 11,221,323 | 0
Corporate Investments [Member] | Diamond Hill Valuation-Weighted 500, L.P. |  |
Summary of market value of investments |  |
Total Investment Portfolio | 0 | 3,398,035
Corporate Investments [Member] | Diamond Hill High Yield Fund, L.P. |  |
Summary of market value of investments |  |
Total Investment Portfolio | 9,874,099 | 9,764,814
Corporate Investments [Member] | Diamond Hill Global Fund, L.P. |  |
Summary of market value of investments |  |
Total Investment Portfolio | 1,410,010 | 1,489,740
Investments in Deferred Compensation Plans [Member] |  |
Summary of market value of investments |  |
Total Investment Portfolio | $ 7,961,412 | $ 5,678,764

X
- Definition Market value of investments. + References No definition available. + Details
Name: | dhil_MarketValueOfInvestmentsAbstract
Namespace Prefix: | dhil_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sum of the carrying amounts as of the balance sheet date of all investments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(h)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_Investments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_InvestmentTypeAxis=dhil_CorporateInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentHoldingAxis=dhil_MidCapFundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentHoldingAxis=dhil_ResearchOpportunitiesFundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentHoldingAxis=dhil_FinancialLongShortFundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentHoldingAxis=dhil_DiamondHillValuationWeighted500ETFMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentHoldingAxis=dhil_DiamondHillValuationWeightedFiveHundredLpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentHoldingAxis=dhil_HIghYieldFundLPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentHoldingAxis=dhil_GlobalFundLPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=dhil_InvestmentsinDeferredCompensationPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |