Condensed Consolidated Statements of Equity (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Balance (in shares) at Dec. 31, 2020		3,971	25,777,796
Balance at Dec. 31, 2020	$ 538,960	$ 0	$ 3	$ 310,326	$ 203,080	$ (823)	$ 26,374
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock and other, net of shares withheld for employer taxes (in shares)			396,818
Vesting of restricted stock and other, net of shares withheld for employer taxes	(10,539)			(10,539)
Common stock issued, net of offering costs (in shares)			1,413,045
Common stock issued, net of offering costs	64,713			64,713
Common stock repurchased and retired (in shares)			(44,650)
Common stock repurchased and retired	(2,656)			(2,656)
Preferred stock issued (in shares)		514
Preferred stock issued	13,997			13,997
Share based payments	23,508			23,508
Warrants exercised (in shares)			11,655
Dividends on common stock	(250,763)				(250,763)
Dividends on preferred stock	(5,467)				(5,467)
Net income (loss)	383,356				380,882		2,474
Remeasurement of B. Riley Principal 150 and 250 Merger Corporations subsidiary temporary equity	(18,182)				(18,182)
Distributions to noncontrolling interests	(14,695)						(14,695)
Contributions from noncontrolling interests	12,734						12,734
Acquisition of noncontrolling interests	13,625						13,625
Other comprehensive loss	(1,384)					(1,384)
Balance (in shares) at Sep. 30, 2021		4,485	27,554,664
Balance at Sep. 30, 2021	747,207	$ 0	$ 3	399,349	309,550	(2,207)	40,512
Balance (in shares) at Jun. 30, 2021		4,275	27,580,300
Balance at Jun. 30, 2021	743,565	$ 0	$ 3	387,084	320,078	(1,178)	37,578
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock and other, net of shares withheld for employer taxes (in shares)			7,359
Vesting of restricted stock and other, net of shares withheld for employer taxes	(169)			(169)
Common stock repurchased and retired	(2,656)			(2,656)
Preferred stock issued (in shares)		210
Preferred stock issued	5,716			5,716
Share based payments	9,374			9,374
Warrants exercised (in shares)			11,655
Dividends on common stock	(59,149)				(59,149)
Dividends on preferred stock	(1,929)				(1,929)
Net income (loss)	51,658				50,550		1,108
Distributions to noncontrolling interests	(841)						(841)
Contributions from noncontrolling interests	2,084						2,084
Acquisition of noncontrolling interests	583						583
Other comprehensive loss	(1,029)					(1,029)
Balance (in shares) at Sep. 30, 2021		4,485	27,554,664
Balance at Sep. 30, 2021	747,207	$ 0	$ 3	399,349	309,550	(2,207)	40,512
Balance (in shares) at Dec. 31, 2021		4,512	27,591,028
Balance at Dec. 31, 2021	705,201	$ 0	$ 3	413,486	248,862	(1,080)	43,930
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock and other, net of shares withheld for employer taxes (in shares)			404,668
Vesting of restricted stock and other, net of shares withheld for employer taxes	(6,733)			(6,733)
Common stock repurchased and retired (in shares)			(571)
Common stock repurchased and retired	(27)			(27)
Preferred stock issued (in shares)		23
Preferred stock issued	639			639
Shares issued for the acquisition of FocalPoint (in shares)			304,878
Shares issued for the acquisition of FocalPoint	20,320			20,320
Share based payments	45,713			45,713
Share based payments in equity of subsidiary	57			57
Vesting of shares in equity of subsidiary	0			(35)			35
Dividends on common stock	(93,128)				(93,128)
Dividends on preferred stock	(6,006)				(6,006)
Net income (loss)	(91,633)				(102,384)		10,751
Remeasurement of B. Riley Principal 150 and 250 Merger Corporations subsidiary temporary equity	(428)				(428)
Distributions to noncontrolling interests	(2,167)						(2,167)
Contributions from noncontrolling interests	11,350						11,350
Acquisition of noncontrolling interests	182						182
Other comprehensive loss	(5,646)					(5,646)
Balance (in shares) at Sep. 30, 2022		4,535	28,300,003
Balance at Sep. 30, 2022	577,694	$ 0	$ 3	473,420	46,916	(6,726)	64,081
Balance (in shares) at Jun. 30, 2022		4,535	28,290,458
Balance at Jun. 30, 2022	543,376	$ 0	$ 3	459,220	32,570	(3,884)	55,467
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock and other, net of shares withheld for employer taxes (in shares)			10,116
Vesting of restricted stock and other, net of shares withheld for employer taxes	(293)			(293)
Common stock repurchased and retired (in shares)			(571)
Common stock repurchased and retired	(27)			(27)
Share based payments	14,498			14,498
Share based payments in equity of subsidiary	57			57
Vesting of shares in equity of subsidiary	0			(35)			35
Dividends on common stock	(31,061)				(31,061)
Dividends on preferred stock	(2,002)				(2,002)
Net income (loss)	54,024				47,837		6,187
Remeasurement of B. Riley Principal 150 and 250 Merger Corporations subsidiary temporary equity	(428)				(428)
Distributions to noncontrolling interests	(431)						(431)
Contributions from noncontrolling interests	2,823						2,823
Other comprehensive loss	(2,842)					(2,842)
Balance (in shares) at Sep. 30, 2022		4,535	28,300,003
Balance at Sep. 30, 2022	$ 577,694	$ 0	$ 3	$ 473,420	$ 46,916	$ (6,726)	$ 64,081