XML 61 R26.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Business And Organization (Details) | Dec. 31, 2012 Subsidiary
--- | ---
Business and Organization (Textual) [Abstract] |
Number of operating subsidiaries | 3

X
- Details
Name: | dhil_BusinessAndOrganizationTextualAbstract
Namespace Prefix: | dhil_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of operating subsidiaries. + References No definition available. + Details
Name: | dhil_NumberOfOperatingSubsidiaries
Namespace Prefix: | dhil_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant