Segment Analysis (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 item	Sep. 30, 2011
Segment Analysis
Number of business segments			4
Information concerning operations
Investment (losses)/gains, net	$ 163	$ 2,857	$ 156	$ 2,539
Gain from bargain purchase - ClearPoint acquisition				2,330
Investment banking	1,996	9,359	17,788	29,723
Interest income	6,879	16,249	37,632	46,201
Interest expense	(2,149)	(2,672)	(10,261)	(8,295)
Net revenues	43,330	54,164	152,718	199,932
Income/(loss) before income taxes from continuing operations - Reportable segments	(5,024)	(78,785)	(42,057)	(61,640)
Reportable segments
Information concerning operations
Net revenues	42,145	49,253	147,471	190,010
Income/(loss) before income taxes from continuing operations - Reportable segments	4,972	5,955	6,731	36,625
MBS & Rates
Information concerning operations
Sales and trading	4,162	(190)	9,023	52,791
Investment banking	10	2,257	632	3,558
Interest income	5,953	15,178	32,720	43,374
Interest expense	(1,924)	(3,531)	(10,051)	(10,549)
Other revenue	742		2,232	15
Net revenues	8,943	13,714	34,556	89,189
Income/(loss) before income taxes from continuing operations - Reportable segments	1,814	4,247	5,556	29,655
Corporate Credit
Information concerning operations
Sales and trading	17,776	15,345	54,982	47,502
Investment banking	487	27	2,394	2,491
Interest income	266	321	622	1,169
Interest expense	(122)	(140)	(341)	(456)
Other revenue	397	169	736	332
Net revenues	18,804	15,722	58,393	51,038
Income/(loss) before income taxes from continuing operations - Reportable segments	3,939	3,495	4,536	6,338
Investment banking
Information concerning operations
Investment banking	1,499	7,075	14,762	23,674
Net revenues	1,499	7,075	14,762	23,674
Income/(loss) before income taxes from continuing operations - Reportable segments	(257)	(1,452)	2,517	3,539
ClearPoint
Information concerning operations
Number of states across the country in which the entity originates, processes and underwrites loans			43
Sales and trading	11,553	10,660	34,045	22,116
Interest income	711	746	4,148	1,648
Interest expense	(952)	(714)	(4,107)	(1,572)
Other revenue	1,587	2,050	5,674	3,917
Net revenues	12,899	12,742	39,760	26,109
Income/(loss) before income taxes from continuing operations - Reportable segments	(524)	(335)	(5,878)	(2,907)
Other
Information concerning operations
Investment (losses)/gains, net	163	2,857	156	2,539
Sales and trading	(9)	(56)	(9)	(50)
Gain from bargain purchase - ClearPoint acquisition				2,330
Interest income	(51)	4	142	10
Interest expense	(21)	(27)	(86)	(1,447)
Interest expense	870	1,740	4,324	5,729
Other revenue	233	393	720	811
Net revenues	1,185	4,911	5,247	9,922
Income/(loss) before income taxes from continuing operations - Reportable segments	$ (9,996)	$ (84,740)	$ (48,788)	$ (98,265)