Loans and Leases and the Allowance for Loan and Lease Losses (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Allowance for Loan and Lease Losses:
Balance at the beginning of the period	$ 138,606	$ 147,358
Loans and Leases Charged-Off	(24,159)	(36,760)
Recoveries on Loans and Leases Previously Charged-Off	13,431	15,318
Net Loans and Leases Charged-Off	(10,728)	(21,442)
Provision for Credit Losses	979	12,690	55,287
Balance at end of the period	128,857	138,606	147,358
Allowance for Loan and Lease Losses:
Individually Evaluated for Impairment	3,725	5,451
Collectively Evaluated for Impairment	125,132	133,155
Total	128,857	138,606	147,358
Recorded Investment in Loans and Leases:
Individually Evaluated for Impairment	50,598	47,600
Collectively Evaluated for Impairment	5,803,923	5,490,704
Total Loans and Leases	5,854,521	5,538,304	5,335,792	5,759,785	6,530,233
Commercial
Allowance for Loan and Lease Losses:
Balance at the beginning of the period	80,562	80,977
Loans and Leases Charged-Off	(3,947)	(8,112)
Recoveries on Loans and Leases Previously Charged-Off	4,191	6,500
Net Loans and Leases Charged-Off	244	(1,612)
Provision for Credit Losses	(8,102)	1,197
Balance at end of the period	72,704	80,562
Allowance for Loan and Lease Losses:
Individually Evaluated for Impairment	161	1,195
Collectively Evaluated for Impairment	72,543	79,367
Total	72,704	80,562
Recorded Investment in Loans and Leases:
Individually Evaluated for Impairment	13,098	15,135
Collectively Evaluated for Impairment	2,302,795	2,150,882
Total Loans and Leases	2,315,893	2,166,017	2,051,331	2,157,926	2,416,652
Consumer
Allowance for Loan and Lease Losses:
Balance at the beginning of the period	58,044	66,381
Loans and Leases Charged-Off	(20,212)	(28,648)
Recoveries on Loans and Leases Previously Charged-Off	9,240	8,818
Net Loans and Leases Charged-Off	(10,972)	(19,830)
Provision for Credit Losses	9,081	11,493
Balance at end of the period	56,153	58,044
Allowance for Loan and Lease Losses:
Individually Evaluated for Impairment	3,564	4,256
Collectively Evaluated for Impairment	52,589	53,788
Total	56,153	58,044
Recorded Investment in Loans and Leases:
Individually Evaluated for Impairment	37,500	32,465
Collectively Evaluated for Impairment	3,501,128	3,339,822
Total Loans and Leases	$ 3,538,628	$ 3,372,287	$ 3,284,461	$ 3,601,859	$ 4,113,581