Other Comprehensive Income (Loss) (Reclassifications out of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 29,882	$ 35,331	$ 89,894	$ 117,479
Income tax benefit	27,765	(211)	72,114	(2,393)
Investment securities gains, net	1,124	6,656	2,571	30,909
Salaries and other personnel expense	187,328	191,492	550,799	602,890
Reclassifications, net of income taxes	37,188	16,030	82,704	62,202
Net Unrealized Gains (Losses) on Cash Flow Hedges [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	(112)		(336)
Income tax benefit	43		131
Reclassifications, net of income taxes	(69)		(205)
Net Unrealized Gains (Losses) on Investment Securities Available for Sale [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit	(433)		(990)
Investment securities gains, net	1,124		2,571
Reclassifications, net of income taxes	691		1,581
Amortization of Post-Retirement Unfunded Health Benefit [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit	(28)		(38)
Salaries and other personnel expense	72		98
Reclassifications, net of income taxes	$ 44		$ 60