Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net income	$ 58,669	$ 54,507	$ 177,764	$ 162,121
Other comprehensive income (loss), before tax:
Change in net unrealized gain/loss during the period	40,122	78,552	62,972	169,516
Reclassification adjustment for net (gains) losses included in net income		(6,409)	121	(6,414)
Total securities available for sale	40,122	72,143	63,093	163,102
Defined-benefit post-retirement benefit plans:
Change in the net actuarial gain/loss	1,427	783	4,084	2,348
Derivatives:
Change in the accumulated gain/loss on effective cash flow hedge derivatives	(269)	(909)	(760)	(2,560)
Reclassification adjustments for (gains) losses included in net income:
Interest rate swaps on variable-rate loans	(9,345)	(9,345)	(28,035)	(28,035)
Interest rate swap on junior subordinated deferrable interest debentures	1,063	1,118	3,140	3,304
Total derivatives	(8,551)	(9,136)	(25,655)	(27,291)
Other comprehensive income (loss), before tax	32,998	63,790	41,522	138,159
Deferred tax expense (benefit) related to other comprehensive income	11,550	22,326	14,533	48,356
Other comprehensive income (loss), net of tax	21,448	41,464	26,989	89,803
Comprehensive income	$ 80,117	$ 95,971	$ 204,753	$ 251,924