Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 81,948	$ 16,400	$ 11,935
Other comprehensive income (loss):
Change in cumulative translation adjustment	173	(1,627)	1,178
Other comprehensive income (loss), net of tax	173	(1,627)	1,178
Total comprehensive income	82,121	14,773	13,113
Comprehensive income attributable to noncontrolling interests	337	891	379
Comprehensive income attributable to B. Riley Financial, Inc.	$ 81,784	$ 13,882	$ 12,734