BUSINESS SEGMENTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenues - Services and fees									$ 67,257	$ 59,967	$ 65,624
Revenues - Sale of goods									9,859	16,165	18,312
Total revenues	19,842	20,674	14,947	21,653	18,188	21,751	15,239	20,954	77,116	76,132	83,936
Direct cost of services									(23,466)	(24,146)	(23,911)
Cost of goods sold									(14,080)	(11,506)	(12,750)
Selling, general, and administrative expenses									(44,453)	(36,382)	(39,834)
Restructuring charge		2,548							2,548	0	0
Depreciation and Amortization									(646)	(611)	(626)
Segment income	(3,669)	(1,253)	(1,056)	(1,258)	2,906	782	(1,935)	2,345	(7,431)	4,098	7,441
Corporate and other expenses									(11,621)	(11,638)	(11,002)
Interest income									12	26	201
Loss from equity investment in Great American Real Estate, LLC and Shoon Trading Limited									0	(21)	(120)
Gain from bargain purchase									0	0	1,366
Interest expense									(1,262)	(2,667)	(2,612)
(Loss) income before income taxes									(8,681)	1,280	6,276
Provision for income taxes	(1,091)	(387)	(594)	(814)	1,046	(133)	(987)	778	2,886	(704)	(1,936)
Net (loss) income	(2,902)	(916)	(907)	(1,070)	1,000	236	(1,595)	935	(5,795)	576	4,340
Net income (loss) attributable to noncontrolling interests									6	(482)	819
Net (loss) income attributable to B. Riley Financial, Inc.	(2,822)	(868)	(777)	(1,334)	934	366	(1,531)	1,289	(5,801)	1,058	3,521
Capital expenditures									143	1,160	634
Total assets	138,990				73,677				138,990	73,677
Valuation and Appraisal Reportable Segment [Member]
Segment Reporting Information [Line Items]
Revenues - Services and fees									30,671	27,558	25,492
Direct cost of services									(12,747)	(13,026)	(11,584)
Selling, general, and administrative expenses									(10,721)	(8,718)	(6,974)
Restructuring charge									(203)	0	0
Depreciation and Amortization									(151)	(143)	(121)
Segment income									6,849	5,671	6,813
Capital expenditures									1	418	134
Total assets	9,527				8,611				9,527	8,611
Consolidated Reportable Segment [Member]
Segment Reporting Information [Line Items]
Segment income									4,190	15,736	18,443
Auction and Liquidation Reportable Segment [Member]
Segment Reporting Information [Line Items]
Revenues - Services and fees									17,166	32,409	40,132
Revenues - Sale of goods									9,859	9,963	8,106
Total revenues									27,025	42,372	48,238
Direct cost of services									(10,719)	(11,120)	(12,327)
Cost of goods sold									(14,080)	(7,940)	(7,275)
Selling, general, and administrative expenses									(8,481)	(11,889)	(17,064)
Restructuring charge									(1,339)
Depreciation and Amortization									(107)	(176)	(193)
Segment income									(7,701)	11,247	11,379
Capital expenditures									38	423	394
Total assets	41,360				24,222				41,360	24,222
Uk Retail Stores Segment [Member]
Segment Reporting Information [Line Items]
Revenues - Sale of goods									0	6,202	10,206
Cost of goods sold									0	(3,566)	(5,475)
Selling, general, and administrative expenses									0	(3,773)	(4,462)
Depreciation and Amortization									0	(45)	(18)
Segment income									0	(1,182)	251
Capital expenditures									0	319	106
Total assets					0					0
Capital markets reportable segment [Member]
Segment Reporting Information [Line Items]
Revenues - Services and fees									19,420	0
Revenues - Sale of goods											0
Selling, general, and administrative expenses									(14,185)	0	0
Depreciation and Amortization									(193)	0	0
Segment income									5,042	0	0
Capital expenditures									104	0	0
Total assets	48,878				0				48,878	0
Corporate and Other segment [Member]
Segment Reporting Information [Line Items]
Total assets	$ 39,225				$ 40,844				$ 39,225	$ 40,844