Loans And Allowance For Loan Losses (Aging Information On Past Due And Accruing Loans) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	$ 11,365,009	$ 10,839,081
30 – 89 Days Past Due	49,796	54,975
90 Days Past Due and Still Accruing	13,658	13,966
Non-accrual	40,775	48,814
Total	11,469,238	10,956,836
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	3,969,952	3,715,319
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	403,507	406,197
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	2,288,215	2,313,550
Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	1,883,092	1,787,626
Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	1,705,134	1,512,716
Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	782,370	796,228
Overdrafts [Member]
Loans And Allowance For Loan Losses [Line Items]
Total	6,095	4,611
Commercial Portfolio Segment [Member] | Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	3,946,144	3,697,589
30 – 89 Days Past Due	11,152	5,467
90 Days Past Due and Still Accruing	1,096	671
Non-accrual	11,560	11,592
Total	3,969,952	3,715,319
Commercial Portfolio Segment [Member] | Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	397,488	386,423
30 – 89 Days Past Due	827	9,601
90 Days Past Due and Still Accruing	35	0
Non-accrual	5,157	10,173
Total	403,507	406,197
Commercial Portfolio Segment [Member] | Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	2,266,688	2,292,385
30 – 89 Days Past Due	3,661	1,340
90 Days Past Due and Still Accruing	0	47
Non-accrual	17,866	19,778
Total	2,288,215	2,313,550
Personal Banking Portfolio Segment [Member] | Real Estate - Personal [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,868,606	1,771,231
30 – 89 Days Past Due	6,618	9,755
90 Days Past Due and Still Accruing	1,676	1,560
Non-accrual	6,192	5,080
Total	1,883,092	1,787,626
Personal Banking Portfolio Segment [Member] | Consumer [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,687,285	1,492,960
30 – 89 Days Past Due	16,053	17,482
90 Days Past Due and Still Accruing	1,796	2,274
Non-accrual	0	0
Total	1,705,134	1,512,716
Personal Banking Portfolio Segment [Member] | Revolving Home Equity [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	428,478	416,614
30 – 89 Days Past Due	1,552	1,082
90 Days Past Due and Still Accruing	843	702
Non-accrual	0	2,191
Total	430,873	420,589
Personal Banking Portfolio Segment [Member] | Consumer Credit Card [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	764,599	777,564
30 – 89 Days Past Due	9,559	9,952
90 Days Past Due and Still Accruing	8,212	8,712
Non-accrual	0	0
Total	782,370	796,228
Personal Banking Portfolio Segment [Member] | Overdrafts [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	5,721	4,315
30 – 89 Days Past Due	374	296
90 Days Past Due and Still Accruing	0	0
Non-accrual	0	0
Total	$ 6,095	$ 4,611