NET CAPITAL REQUIREMENTS (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
B. Riley Securities (“BRS”)
Broker-Dealer, Net Capital Requirement [Line Items]
Net capital	$ 115,953	$ 134,561
Excess capital	112,151	130,163
Required minimum net capital	3,802	4,398
B. Riley Wealth Management (“BRWM”)
Broker-Dealer, Net Capital Requirement [Line Items]
Net capital	13,996	12,328
Excess capital	12,253	10,431
Required minimum net capital	$ 1,743	$ 1,897

Broker Dealer, Net Capital Requirement [Line Items]

No definition available.

Name:	rily_BrokerDealerNetCapitalRequirementLineItems
Namespace Prefix:	rily_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of net capital in excess of minimum required net capital, calculated under Alternative Standard.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Rule 15c3-1
-Number 240
-Section 15c3-1
-Publisher SEC

Name:	srt_AlternativeExcessNetCapital
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Minimum amount of net capital of broker-dealer and its subsidiary, calculated under Alternative Standard.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Rule 15c3-1
-Number 240
-Section 15c3-1
-Publisher SEC

Name:	srt_AlternativeNetCapitalRequirement1
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of net capital of broker-dealer.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Rule 15c3-1
-Number 240
-Section 15c3-1
-Publisher SEC

Name:	dei_LegalEntityAxis=rily_BRileySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=rily_BRileyWealthManagementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: