XML 53 R27.htm IDEA: XBRL DOCUMENT v3.19.3

Significant Accounting Policies - Revenues From Contracts with Customers (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 34,592,372	$ 37,471,647	$ 100,716,763	$ 111,181,363
Investment advisory
Disaggregation of Revenue [Line Items]
Revenue	32,498,101	34,928,205	94,521,491	103,085,767
Mutual fund administration revenue, net
Disaggregation of Revenue [Line Items]
Revenue	2,094,271	2,543,442	6,195,272	8,095,596
Proprietary funds
Disaggregation of Revenue [Line Items]
Revenue	26,272,711	29,408,277	78,288,958	88,560,537
Proprietary funds | Investment advisory
Disaggregation of Revenue [Line Items]
Revenue	24,178,440	26,864,835	72,093,686	80,464,941
Proprietary funds | Mutual fund administration revenue, net
Disaggregation of Revenue [Line Items]
Revenue	2,094,271	2,543,442	6,195,272	8,095,596
Sub-advised funds and separately managed accounts
Disaggregation of Revenue [Line Items]
Revenue	8,319,661	8,063,370	22,427,805	22,620,826
Sub-advised funds and separately managed accounts | Investment advisory
Disaggregation of Revenue [Line Items]
Revenue	8,319,661	8,063,370	22,427,805	22,620,826
Sub-advised funds and separately managed accounts | Mutual fund administration revenue, net
Disaggregation of Revenue [Line Items]
Revenue	$ 0	$ 0	$ 0	$ 0

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DisaggregationOfRevenueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

+ Details

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	srt_ProductOrServiceAxis=dhil_InvestmentAdvisoryServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=dhil_MutualFundAdministrativeServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=dhil_ProprietaryFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_MajorCustomersAxis=dhil_SubadvisedFundsAndInstitutionalAccountsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: