Segment Analysis (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 item	Dec. 31, 2011	Dec. 31, 2010
Segment Analysis
Number of business segments	4
Information concerning operations
Investment gains, net	$ 1,233	$ 2,996	$ 7
Gain from bargain purchase - ClearPoint acquisition		2,330
Investment banking	30,553	33,069	43,400
Interest income	48,796	66,194	57,292
Interest expense	(12,827)	(11,913)	(11,318)
Net revenues	203,595	261,172	248,582
Income (loss) from continuing operations before income taxes	(53,353)	(61,877)	(25,783)
Reportable segments
Information concerning operations
Net revenues	195,886	248,448	243,257
Income (loss) from continuing operations before income taxes	2,559	41,462	36,463
Investment banking
Information concerning operations
Investment banking	27,441	26,610	37,276
Other revenue			90
Net revenues	27,441	26,610	37,366
Income (loss) from continuing operations before income taxes	4,578	2,290	(2,220)
MBS & Rates
Information concerning operations
Sales and trading	7,348	53,753	76,897
Investment banking	682	3,924	1,513
Interest income	42,910	60,920	55,565
Interest expense	(12,758)	(14,754)	(15,535)
Other revenue	2,456	15	217
Net revenues	40,638	103,858	118,657
Income (loss) from continuing operations before income taxes	127	33,120	33,347
Credit Products
Information concerning operations
Sales and trading	70,639	66,688	79,357
Investment banking	2,430	2,535	6,558
Interest income	882	1,817	1,878
Interest expense	(496)	(551)	(632)
Other revenue	977	567	73
Net revenues	74,432	71,056	87,234
Income (loss) from continuing operations before income taxes	3,745	9,738	5,336
ClearPoint
Information concerning operations
Sales and trading	46,283	40,119
Interest income	4,935	3,446
Interest expense	(5,131)	(2,927)
Other revenue	7,288	6,286
Net revenues	53,375	46,924
Income (loss) from continuing operations before income taxes	(5,891)	(3,686)
Other
Information concerning operations
Investment gains, net	1,233	2,996	7
Sales and trading	(81)	(104)	(3)
Gain from bargain purchase - ClearPoint acquisition		2,330
Interest income	69	11	(151)
Interest expense	(109)	(1,231)	(3,476)
Interest expense - Intersegment allocations	5,667	7,550	8,325
Other revenue	930	1,172	623
Net revenues	7,709	12,724	5,325
Income (loss) from continuing operations before income taxes	$ (55,912)	$ (103,339)	$ (62,246)