Loans and Allowance for Loan Losses (Schedule Of Current, Accruing Past Due And Nonaccrual Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	$ 21,695,687	$ 20,879,481
Accruing 30-89 Days Past Due	36,350	46,614
Accruing 90 Days or Greater Past Due	2,998	4,637
Total Accruing Past Due	39,348	51,251
Non-accrual	157,640	197,757
Total loans	21,892,675	21,128,489	$ 20,617,415
Deferred fees and costs, net	28,400	30,800	$ 28,800
Home Equity Lines [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	1,662,930	1,659,869
Accruing 30-89 Days Past Due	4,557	6,992
Accruing 90 Days or Greater Past Due	297	703
Total Accruing Past Due	4,854	7,695
Non-accrual	16,263	16,434
Total loans	1,684,047	1,683,998
Consumer Mortgages [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	1,857,640	1,648,145
Accruing 30-89 Days Past Due	6,284	12,626
Accruing 90 Days or Greater Past Due	378	12
Total Accruing Past Due	6,662	12,638
Non-accrual	24,154	33,278
Total loans	1,888,456	1,694,061
Credit Cards [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	238,519	250,304
Accruing 30-89 Days Past Due	1,473	1,971
Accruing 90 Days or Greater Past Due	1,323	1,374
Total Accruing Past Due	2,796	3,345
Non-accrual	0	0
Total loans	241,315	253,649
Other Retail Loans [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	340,277	297,703
Accruing 30-89 Days Past Due	3,128	2,361
Accruing 90 Days or Greater Past Due	187	101
Total Accruing Past Due	3,315	2,462
Non-accrual	1,833	2,295
Total loans	345,425	302,460
Investment Properties [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	5,544,594	5,184,103
Accruing 30-89 Days Past Due	2,400	1,851
Accruing 90 Days or Greater Past Due	0	0
Total Accruing Past Due	2,400	1,851
Non-accrual	10,582	20,720
Total loans	5,557,576	5,206,674
1-4 Family Properties [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	1,073,356	1,105,186
Accruing 30-89 Days Past Due	4,122	4,067
Accruing 90 Days or Greater Past Due	81	432
Total Accruing Past Due	4,203	4,499
Non-accrual	16,994	24,197
Total loans	1,094,553	1,133,882
Land Acquisition [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	517,728	551,308
Accruing 30-89 Days Past Due	1,322	363
Accruing 90 Days or Greater Past Due	67	0
Total Accruing Past Due	1,389	363
Non-accrual	19,010	34,375
Total loans	538,127	586,046
Commercial Real Estate [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	7,135,678	6,840,597
Accruing 30-89 Days Past Due	7,844	6,281
Accruing 90 Days or Greater Past Due	148	432
Total Accruing Past Due	7,992	6,713
Non-accrual	46,586	79,292
Total loans	7,190,256	6,926,602
Commercial, Financial and Agricultural [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	6,219,484	6,130,184
Accruing 30-89 Days Past Due	7,095	9,979
Accruing 90 Days or Greater Past Due	533	1,790
Total Accruing Past Due	7,628	11,769
Non-accrual	50,656	40,359
Total loans	6,277,768	6,182,312
Owner-Occupied [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	4,241,159	4,052,679
Accruing 30-89 Days Past Due	5,969	6,404
Accruing 90 Days or Greater Past Due	132	225
Total Accruing Past Due	6,101	6,629
Non-accrual	18,148	26,099
Total loans	4,265,408	4,085,407
Commercial and Industrial [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	10,460,643	10,182,863
Accruing 30-89 Days Past Due	13,064	16,383
Accruing 90 Days or Greater Past Due	665	2,015
Total Accruing Past Due	13,729	18,398
Non-accrual	68,804	66,458
Total loans	10,543,176	10,267,719
Retail [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	4,099,366	3,856,021
Accruing 30-89 Days Past Due	15,442	23,950
Accruing 90 Days or Greater Past Due	2,185	2,190
Total Accruing Past Due	17,627	26,140
Non-accrual	42,250	52,007
Total loans	$ 4,159,243	$ 3,934,168