SECURITIES (Information On Securities With At Least One Rating) (Details) (USD $) In Thousands, unless otherwise specified				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Cwhl 2006-18 2a7 [Member]	Dec. 31, 2011 Cwalt 2005-46cb A1 [Member]	Dec. 31, 2011 Cwalt 2005-J8 1a3 [Member]	Dec. 31, 2011 Chase 2005-S3 A4 [Member]	Dec. 31, 2011 Chase 2006-S3 1a5 [Member]	Dec. 31, 2011 Cmsi 2007-61a5 [Member]	Dec. 31, 2011 Gsr 2006-10f 1a1 [Member]	Dec. 31, 2011 Malt 2004-6 7 A1 [Member]	Dec. 31, 2011 Mana 2007-F1 1a1 [Member]	Dec. 31, 2011 Rfmsi 2006-S5 A14 [Member]	Dec. 31, 2012 Rali 2004-Qs7 A3 [Member]
Committee On Uniform Securities Identification Procedures				12543WAJ7	12667G6U2	12667GJ20	16162WNE5	16162XAE7	173103AE2	36266WAC6	576434SK1	59023YAA2	74957EAP2	76110HTX7
Other Than Temporary Impairment	$ 0	$ 359	$ 1,812	$ 0	$ 42	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 317	$ 0
Par Balance		27,098		2,815	3,530	5,043	333	1,281	2,523	3,626	3,072	2,168	2,707	2,908
Amortized cost		25,934		2,761	3,323	4,835	331	1,279	2,521	3,374	3,052	2,126	2,332	2,891
Fair Value		23,745		2,450	2,747	4,560	330	1,199	2,473	3,164	3,048	1,745	2,029	2,979
Unrealized Gain(Loss)		$ (2,189)		$ (311)	$ (576)	$ (275)	$ (1)	$ (80)	$ (48)	$ (210)	$ (4)	$ (381)	$ (303)	$ 88
Debt Instrument, Credit Rating				C	CC	CC	B1	C	B1	C	B1	D	D	BB+
Constant Default Rate 30 Days				12.89%	5.42%	7.90%	0.00%	0.84%	5.29%	0.00%	0.00%	0.00%	6.03%	5.67%
Constant Default Rate 90 Days				8.16%	3.95%	8.60%	0.00%	1.20%	3.04%	0.00%	0.00%	0.00%	4.98%	5.46%
Constant Default Rate 120 Days				4.06%	3.16%	5.04%	2.43%	2.73%	2.69%	1.13%	0.00%	0.00%	5.45%	3.38%
Credit Support				2.89%	3.01%	6.20%	4.02%	2.20%	6.68%	2.17%	11.30%	0.00%	0.00%	10.34%