Segment Analysis (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 segment	Jun. 30, 2011
Segment Analysis
Number of business segments			4
Information concerning operations
Investment (losses)/gains, net	$ (139)	$ 368	$ (7)	$ (318)
Gain from bargain purchase - ClearPoint acquisition				2,330
Investment banking	9,115	10,042	15,793	20,364
Interest income	11,558	14,884	30,762	29,952
Interest expense	(3,502)	(3,055)	(8,121)	(5,624)
Net revenues	44,647	56,379	109,390	145,768
(Loss)/income before income taxes from continuing operations	(31,751)	2,416	(37,033)	17,144
Reportable segments
Information concerning operations
Net revenues	43,200	54,585	105,326	140,758
(Loss)/income before income taxes from continuing operations	(778)	9,450	1,747	30,670
MBS & Rates
Information concerning operations
Sales and trading	(1,653)	12,246	6,350	52,997
Investment banking	385	1,128	623	1,300
Interest income	10,340	13,908	26,767	28,197
Interest expense	(3,790)	(3,512)	(8,127)	(7,018)
Net revenues	5,282	23,770	25,613	75,476
(Loss)/income before income taxes from continuing operations	(1,746)	6,542	3,741	25,407
Corporate Credit
Information concerning operations
Sales and trading	17,769	14,679	37,546	32,320
Investment banking		(42)	1,907	2,464
Interest income	223	386	355	848
Interest expense	(120)	(172)	(219)	(316)
Net revenues	17,872	14,851	39,589	35,316
(Loss)/income before income taxes from continuing operations	1,285	631	597	2,843
Investment banking
Information concerning operations
Investment banking	8,730	8,956	13,263	16,600
Net revenues	8,730	8,956	13,263	16,600
(Loss)/income before income taxes from continuing operations	2,195	3,728	2,774	4,991
ClearPoint
Information concerning operations
Number of states across the country in which the entity originates, processes and underwrites loans			45
Sales and trading	11,396	6,990	26,579	13,323
Interest income	993	587	3,437	902
Interest expense	(1,073)	(569)	(3,155)	(859)
Net revenues	11,316	7,008	26,861	13,366
(Loss)/income before income taxes from continuing operations	(2,512)	(1,451)	(5,365)	(2,571)
Other
Information concerning operations
Investment (losses)/gains, net	(139)	368	(7)	(318)
Sales and trading	103	225	487	424
Gain from bargain purchase - ClearPoint acquisition				2,330
Interest income	2	3	203	5
Interest expense	(40)	(827)	(97)	(1,420)
Interest expense	1,521	2,025	3,478	3,989
Net revenues	1,447	1,794	4,064	5,010
(Loss)/income before income taxes from continuing operations	$ (30,973)	$ (7,034)	$ (38,780)	$ (13,526)