Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (9,196)	$ 256,598
Other comprehensive income (loss):
Change in cumulative translation adjustment	(488)	(636)
Other comprehensive loss, net of tax	(488)	(636)
Total comprehensive (loss) income	(9,684)	255,962
Comprehensive income (loss) attributable to noncontrolling interests	866	1,942
Comprehensive (loss) income attributable to B. Riley Financial, Inc.	$ (10,550)	$ 254,020