Loans And Allowance For Loan Losses (Aging Information On Past Due And Accruing Loans) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	$ 11,323,377	$ 10,839,081
30 - 89 Days Past Due	64,139	54,975
90 Days Past Due and Still Accruing	12,399	13,966
Non-accrual	45,800	48,814
Total	11,445,715	10,956,836
Business [Member] | Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	4,002,376	3,697,589
30 - 89 Days Past Due	6,875	5,467
90 Days Past Due and Still Accruing	682	671
Non-accrual	11,215	11,592
Total	4,021,148	3,715,319
Real Estate - Construction And Land [Member] | Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	372,646	386,423
30 - 89 Days Past Due	9,254	9,601
90 Days Past Due and Still Accruing	0	0
Non-accrual	10,115	10,173
Total	392,015	406,197
Real Estate - Business [Member] | Commercial Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	2,281,922	2,292,385
30 - 89 Days Past Due	7,547	1,340
90 Days Past Due and Still Accruing	0	47
Non-accrual	17,380	19,778
Total	2,306,849	2,313,550
Real Estate - Personal [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,833,181	1,771,231
30 - 89 Days Past Due	14,481	9,755
90 Days Past Due and Still Accruing	1,254	1,560
Non-accrual	5,752	5,080
Total	1,854,668	1,787,626
Consumer [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	1,646,939	1,492,960
30 - 89 Days Past Due	15,277	17,482
90 Days Past Due and Still Accruing	1,663	2,274
Non-accrual	1,338	0
Total	1,665,217	1,512,716
Revolving Home Equity [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	434,097	416,614
30 - 89 Days Past Due	1,125	1,082
90 Days Past Due and Still Accruing	1,525	702
Non-accrual	0	2,191
Total	436,747	420,589
Consumer Credit Card [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	747,214	777,564
30 - 89 Days Past Due	9,335	9,952
90 Days Past Due and Still Accruing	7,275	8,712
Non-accrual	0	0
Total	763,824	796,228
Overdrafts [Member] | Personal Banking Portfolio Segment [Member]
Loans And Allowance For Loan Losses [Line Items]
Current or Less Than 30 Days Past Due	5,002	4,315
30 - 89 Days Past Due	245	296
90 Days Past Due and Still Accruing	0	0
Non-accrual	0	0
Total	$ 5,247	$ 4,611