Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 48,892	$ 34,144	$ 32,172	$ 64,432
Other comprehensive income (loss):
Change in cumulative translation adjustment	526	(521)	(179)	(184)
Other comprehensive income (loss), net of tax	526	(521)	(179)	(184)
Total comprehensive income	49,418	33,623	31,993	64,248
Comprehensive income (loss) attributable to noncontrolling interests	513	(158)	(1,382)	(50)
Comprehensive income attributable to B. Riley Financial, Inc.	$ 48,905	$ 33,781	$ 33,375	$ 64,298