Consolidated Securitization Vehicles (Details 3) (Securitization Vehicles, USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Vintage
2006	$ 15,098	$ 14,884
2005	36,700	7,060
2004	24,762	26,715
2003	14,889	14,885
2002	9,095	8,995
2001	7,691	7,156
2000	26,239	26,811
1999	20,177	30,027
1998	11,979	190,359
1997		32,080
Total	166,630	358,972
HeldToMaturity | AAA
Vintage
2006
2005
2004
2003	9,909	9,908
2002
2001
2000	2,893	2,891
1999
1998		45,956
1997		4,434
Total	12,802	63,189
HeldToMaturity | AA
Vintage
2006
2005
2004		24,780
2003
2002
2001
2000
1999
1998	2,277	46,315
1997
Total	2,277	71,095
HeldToMaturity | A
Vintage
2006
2005
2004	24,762	1,935
2003
2002
2001
2000
1999	5,155	11,233
1998	8,019	37,580
1997		16,159
Total	37,936	66,907
HeldToMaturity | BBB
Vintage
2006
2005
2004
2003	3,007	3,011
2002
2001
2000
1999		1,414
1998		43,607
1997
Total	3,007	48,032
HeldToMaturity | BB
Vintage
2006
2005
2004
2003	1,973	1,966
2002	6,724	6,712
2001
2000	19,354	19,935
1999	15,022	17,380
1998	220	11,901
1997		5,223
Total	43,293	63,117
HeldToMaturity | BRatingMember
Vintage
2006
2005
2004
2003
2002
2001	5,427	5,426
2000
1999
1998
1997		2,762
Total	5,427	8,188
HeldToMaturity | CccAndBelowRatingMember
Vintage
2006	15,098	14,884
2005	36,700	7,060
2004
2003
2002	2,371	2,283
2001	2,264	1,730
2000	3,992	3,985
1999
1998	1,463	5,000
1997		3,502
Total	$ 61,888	$ 38,444