Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net income	$ 320,886	$ 7,555	$ 334,177	$ 12,972
Other comprehensive income (loss):
Change in unrealized gains on investments and MBS available-for-sale	7,714	36,651	12,312	38,594
Realized net gains reclassified from other comprehensive income	(2,502)	(8,297)	(2,644)	(14,298)
Less deferred income tax provision	(3,681)	(3,826)	(3,681)	(2,384)
Net other comprehensive income (loss)	1,531	24,528	5,987	21,912
Comprehensive income	$ 322,417	$ 32,083	$ 340,164	$ 34,884