Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net income for the period	$ 100,999	$ 95,888	$ 206,984	$ 316,648
Other comprehensive income, net of tax:
Unrealized holding gains on investment securities	11,268	18,265	4,460	100,723
Reclassification of HTM securities to AFS Securities	0	0	10,938	0
Reclassification to earnings for realized net fixed income securities losses (gains)	33	7,886	85,845	(20,058)
Reclassification to earnings for net credit-related impairment losses on investment securities	0	0	0	17
Accretion of securities with noncredit-related impairment losses not expected to be sold	0	276	0	835
Net unrealized gains (losses) on other noninterest-bearing investments	(1,881)	454	94	(333)
Net unrealized holding gains (losses) on derivative instruments	10,607	(508)	12,941	1,011
Reclassification adjustment for increase in interest income recognized in earnings on derivatives instruments	(1,830)	(463)	(3,212)	(1,021)
Other comprehensive income	18,197	25,910	111,066	81,174
Comprehensive income	$ 119,196	$ 121,798	$ 318,050	$ 397,822