Loans and leases and the allowance for credit losses (Details 2) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Allowance for credit losses
Beginning balance	$ 903,703	$ 891,265	$ 902,941	$ 878,022
Provision for credit losses	63,000	85,000	138,000	190,000
Consolidation of loan securitization trusts		0		2,752
Net charge-offs
Charge-offs	(71,650)	(105,346)	(154,744)	(211,385)
Recoveries	12,536	23,748	21,392	35,278
Net charge-offs	(59,114)	(81,598)	(133,352)	(176,107)
Ending balance	907,589	894,667	907,589	894,667
Commercial, financial, leasing [Member]
Allowance for credit losses
Beginning balance	215,659		212,579
Provision for credit losses	6,870		21,812
Net charge-offs
Charge-offs	(14,923)		(28,950)
Recoveries	2,273		4,438
Net charge-offs	(12,650)		(24,512)
Ending balance	209,879		209,879
Commercial real estate loans [Member]
Allowance for credit losses
Beginning balance	391,107		400,562
Provision for credit losses	22,735		37,510
Net charge-offs
Charge-offs	(15,915)		(40,494)
Recoveries	3,184		3,533
Net charge-offs	(12,731)		(36,961)
Ending balance	401,111		401,111
Residential real estate loans [Member]
Allowance for credit losses
Beginning balance	87,526		86,351
Provision for credit losses	13,654		29,495
Net charge-offs
Charge-offs	(15,872)		(32,039)
Recoveries	2,033		3,534
Net charge-offs	(13,839)		(28,505)
Ending balance	87,341		87,341
Consumer loans [Member]
Allowance for credit losses
Beginning balance	137,351		133,067
Provision for credit losses	19,852		47,616
Net charge-offs
Charge-offs	(24,940)		(53,261)
Recoveries	5,046		9,887
Net charge-offs	(19,894)		(43,374)
Ending balance	137,309		137,309
Unallocated [Member]
Allowance for credit losses
Beginning balance	72,060		70,382
Provision for credit losses	(111)		1,567
Net charge-offs
Ending balance	$ 71,949		$ 71,949