Allowance for Loan and Lease Losses (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Allowance for Loan and Lease Losses:
Balance at the beginning of the period	$ 115,454	$ 128,857
Loans and Leases Charged-Off	(4,038)	(5,299)
Recoveries on Loans and Leases Previously Charged-Off	2,710	3,320
Net Loans and Leases Charged-Off	(1,328)	(1,979)
Provision for Credit Losses	0	0
Balance at end of the period	114,126	126,878
Allowance for Loan and Lease Losses:
Individually Evaluated for Impairment	12,602	3,703
Collectively Evaluated for Impairment	101,524	123,175
Total	114,126	126,878
Recorded Investment in Loans and Leases:
Individually Evaluated for Impairment	67,595	49,585
Collectively Evaluated for Impairment	6,142,262	5,733,384
Total Loans and Leases	6,209,857	5,782,969	6,095,387
Commercial
Allowance for Loan and Lease Losses:
Balance at the beginning of the period	71,446	72,704
Loans and Leases Charged-Off	(819)	(382)
Recoveries on Loans and Leases Previously Charged-Off	941	797
Net Loans and Leases Charged-Off	122	415
Provision for Credit Losses	(178)	297
Balance at end of the period	71,390	73,416
Allowance for Loan and Lease Losses:
Individually Evaluated for Impairment	8,903	177
Collectively Evaluated for Impairment	62,487	73,239
Total	71,390	73,416
Recorded Investment in Loans and Leases:
Individually Evaluated for Impairment	29,815	13,115
Collectively Evaluated for Impairment	2,542,348	2,313,308
Total Loans and Leases	2,572,163	2,326,423	2,528,433
Consumer
Allowance for Loan and Lease Losses:
Balance at the beginning of the period	44,008	56,153
Loans and Leases Charged-Off	(3,219)	(4,917)
Recoveries on Loans and Leases Previously Charged-Off	1,769	2,523
Net Loans and Leases Charged-Off	(1,450)	(2,394)
Provision for Credit Losses	178	(297)
Balance at end of the period	42,736	53,462
Allowance for Loan and Lease Losses:
Individually Evaluated for Impairment	3,699	3,526
Collectively Evaluated for Impairment	39,037	49,936
Total	42,736	53,462
Recorded Investment in Loans and Leases:
Individually Evaluated for Impairment	37,780	36,470
Collectively Evaluated for Impairment	3,599,914	3,420,076
Total Loans and Leases	$ 3,637,694	$ 3,456,546	$ 3,566,954