XML 51 R39.htm IDEA: XBRL DOCUMENT v3.21.2

Compensation Plans - Expense Recognition of Deferred Compensation (Detail) - Restricted stock	Sep. 30, 2021 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
2019 (Remaining Period)	$ 2,122,796
2020	7,350,636
2021	5,425,275
2022	1,917,736
2023	340,773
Thereafter	31,167
Total	$ 17,188,383

X

- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized current.

+ References

No definition available.

+ Details

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

X

- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized in year five.

+ References

No definition available.

+ Details

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

X

- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized in year four

+ References

No definition available.

+ Details

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

X

- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized in year one.

+ References

No definition available.

+ Details

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

X

- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized in year three.

+ References

No definition available.

+ Details

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

X

- Definition

Employee service share based compensation nonvested awards compensation cost not yet recognized in year two.

+ References

No definition available.

+ Details

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

X

- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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

X

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: