XML 52 R26.htm IDEA: XBRL DOCUMENT v2.4.0.6

Significant Accounting Policies (Details 1) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Assets under management (AUM) subject to incentive fees and the incentive fees
Total AUM Subject to Incentive Fees	$ 306,975,487	$ 175,804,623
Calendar Quarter-End [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Total AUM Subject to Incentive Fees		88,802,491
Calendar Year-End [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Total AUM Subject to Incentive Fees		87,002,132
May 31, 2017 [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Total AUM Subject to Incentive Fees	306,975,487
Incentive Fees Under Method 1 [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Performance Incentive Fees
Incentive Fees Under Method 1 [Member] | Calendar Quarter-End [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Performance Incentive Fees
Incentive Fees Under Method 1 [Member] | Calendar Year-End [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Performance Incentive Fees
Incentive Fees Under Method 1 [Member] | May 31, 2017 [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Performance Incentive Fees
Incentive Fees Under Method 2 [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Performance Incentive Fees	1,146,468
Incentive Fees Under Method 2 [Member] | Calendar Quarter-End [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Performance Incentive Fees
Incentive Fees Under Method 2 [Member] | Calendar Year-End [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Performance Incentive Fees
Incentive Fees Under Method 2 [Member] | May 31, 2017 [Member]
Assets under management (AUM) subject to incentive fees and the incentive fees
Performance Incentive Fees	$ 1,146,468

X

- Definition

Assets under management (AUM) subject to incentive fees and incentive fees.

+ References

No definition available.

+ Details

Name:	dhil_AssetsUnderManagementIncentiveFees
Namespace Prefix:	dhil_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

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

X

- Definition

Amount of revenues earned by the entity based on the investment results achieved, including, but not limited to, revenues related to management of investment fund assets. Excludes fees based upon a percentage of the assets under management, which are not performance-related fees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.13 (a))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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