Consolidated Securitization Vehicles (Details 3) (Securitization Vehicles, USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Vintage
2006	$ 15,130	$ 14,884
2005	36,672	7,060
2004	24,753	26,715
2003	4,982	14,885
2002	9,113	8,995
2001	7,983	7,156
2000	25,947	26,811
1999	19,023	30,027
1998	11,245	190,359
1997		32,080
Total	154,848	358,972
HeldToMaturity | AAA
Vintage
2006
2005
2004
2003		9,908
2002
2001
2000	2,894	2,891
1999
1998		45,956
1997		4,434
Total	2,894	63,189
HeldToMaturity | AA
Vintage
2006
2005
2004		24,780
2003
2002
2001
2000
1999
1998	2,160	46,315
1997
Total	2,160	71,095
HeldToMaturity | A
Vintage
2006
2005
2004		1,935
2003
2002
2001
2000
1999	4,000	11,233
1998	7,397	37,580
1997		16,159
Total	11,397	66,907
HeldToMaturity | BBB
Vintage
2006
2005
2004	24,753
2003	3,005	3,011
2002
2001
2000
1999		1,414
1998		43,607
1997
Total	27,758	48,032
HeldToMaturity | BB
Vintage
2006
2005
2004
2003	1,977	1,966
2002	6,729	6,712
2001
2000	19,056	19,935
1999	15,023	17,380
1998	151	11,901
1997		5,223
Total	42,936	63,117
HeldToMaturity | BRatingMember
Vintage
2006
2005
2004
2003
2002
2001	5,426	5,426
2000
1999
1998
1997		2,762
Total	5,426	8,188
HeldToMaturity | CccAndBelowRatingMember
Vintage
2006	15,130	14,884
2005	36,672	7,060
2004
2003
2002	2,384	2,283
2001	2,557	1,730
2000	3,997	3,985
1999
1998	1,537	5,000
1997		3,502
Total	$ 62,277	$ 38,444