Loans and Leases and the Allowance for Loan and Lease Losses (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007
Allowance for Loan and Lease Losses:
Balance at the beginning of the period	$ 147,358	$ 143,658
Loans and Leases Charged-Off	(36,760)	(69,878)
Recoveries on Loans and Leases Previously Charged-Off	15,318	18,291
Net Loans and Leases Charged-Off	(21,442)	(51,587)
Provision for Credit Losses	12,690	55,287
Balance at end of the period	138,606	147,358
Allowance for Loan and Lease Losses:
Individually Evaluated for Impairment	5,451	4,170
Collectively Evaluated for Impairment	133,155	143,188
Total	138,606	147,358
Recorded Investment in Loans and Leases:
Individually Evaluated for Impairment	47,600	38,033
Collectively Evaluated for Impairment	5,490,704	5,297,759
Total Loans and Leases	5,538,304	5,335,792	5,759,785	6,530,233	6,580,861
Commercial
Allowance for Loan and Lease Losses:
Balance at the beginning of the period	80,977	82,307
Loans and Leases Charged-Off	(8,112)	(25,947)
Recoveries on Loans and Leases Previously Charged-Off	6,500	9,629
Net Loans and Leases Charged-Off	(1,612)	(16,318)
Provision for Credit Losses	1,197	14,988
Balance at end of the period	80,562	80,977
Allowance for Loan and Lease Losses:
Individually Evaluated for Impairment	1,195	1,091
Collectively Evaluated for Impairment	79,367	79,886
Total	80,562	80,977
Recorded Investment in Loans and Leases:
Individually Evaluated for Impairment	15,135	10,827
Collectively Evaluated for Impairment	2,150,882	2,040,504
Total Loans and Leases	2,166,017	2,051,331	2,157,926	2,416,652	2,379,390
Consumer
Allowance for Loan and Lease Losses:
Balance at the beginning of the period	66,381	61,351
Loans and Leases Charged-Off	(28,648)	(43,931)
Recoveries on Loans and Leases Previously Charged-Off	8,818	8,662
Net Loans and Leases Charged-Off	(19,830)	(35,269)
Provision for Credit Losses	11,493	40,299
Balance at end of the period	58,044	66,381
Allowance for Loan and Lease Losses:
Individually Evaluated for Impairment	4,256	3,079
Collectively Evaluated for Impairment	53,788	63,302
Total	58,044	66,381
Recorded Investment in Loans and Leases:
Individually Evaluated for Impairment	32,465	27,206
Collectively Evaluated for Impairment	3,339,822	3,257,255
Total Loans and Leases	$ 3,372,287	$ 3,284,461	$ 3,601,859	$ 4,113,581	$ 4,201,471