Loans And Allowance For Loan Losses (Schedule Of Current, Accruing Past Due And Nonaccrual Loans) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	$ 20,879,481		$ 19,597,760
Accruing 30-89 Days Past Due	46,614		68,111
Accruing 90 Days or Greater Past Due	4,637		4,489
Total Accruing Past Due	51,251		72,600
Non-accrual	197,757		416,300
Total loans	21,128,489	[1]	20,086,660	[2]
Deferred fees and costs, net	30,790		28,862		20,400
Home Equity Lines [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	1,659,869		1,564,578
Accruing 30-89 Days Past Due	6,992		4,919
Accruing 90 Days or Greater Past Due	703		136
Total Accruing Past Due	7,695		5,055
Non-accrual	16,434		17,908
Total loans	1,683,998		1,587,541
Consumer Mortgages [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	1,648,145		1,460,219
Accruing 30-89 Days Past Due	12,626		18,068
Accruing 90 Days or Greater Past Due	12		1,011
Total Accruing Past Due	12,638		19,079
Non-accrual	33,278		39,770
Total loans	1,694,061		1,519,068
Credit Cards [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	250,304		253,422
Accruing 30-89 Days Past Due	1,971		1,917
Accruing 90 Days or Greater Past Due	1,374		1,507
Total Accruing Past Due	3,345		3,424
Non-accrual	0		0
Total loans	253,649		256,846
Other Retail Loans [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	297,703		280,524
Accruing 30-89 Days Past Due	2,361		2,190
Accruing 90 Days or Greater Past Due	101		26
Total Accruing Past Due	2,462		2,216
Non-accrual	2,295		2,038
Total loans	302,460		284,778
Investment Properties [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	5,165,751		4,546,439
Accruing 30-89 Days Past Due	1,851		3,552
Accruing 90 Days or Greater Past Due	0		40
Total Accruing Past Due	1,851		3,592
Non-accrual	20,720		66,454
Total loans	5,188,322		4,616,485
1-4 Family Properties [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	1,106,866		1,144,447
Accruing 30-89 Days Past Due	4,067		6,267
Accruing 90 Days or Greater Past Due	432		527
Total Accruing Past Due	4,499		6,794
Non-accrual	24,197		33,819
Total loans	1,135,562		1,185,060
Land Acquisition [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	542,941		549,936
Accruing 30-89 Days Past Due	363		1,100
Accruing 90 Days or Greater Past Due	0		300
Total Accruing Past Due	363		1,400
Non-accrual	34,120		154,095
Total loans	577,424		705,431
Commercial Real Estate [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	6,815,558		6,240,822
Accruing 30-89 Days Past Due	6,281		10,919
Accruing 90 Days or Greater Past Due	432		867
Total Accruing Past Due	6,713		11,786
Non-accrual	79,037		254,368
Total loans	6,901,308		6,506,976
Commercial, Financial and Agricultural [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	6,173,651		5,812,490
Accruing 30-89 Days Past Due	9,979		18,985
Accruing 90 Days or Greater Past Due	1,790		813
Total Accruing Past Due	11,769		19,798
Non-accrual	40,614		62,977
Total loans	6,226,034		5,895,265
Owner-Occupied [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	4,034,251		3,985,705
Accruing 30-89 Days Past Due	6,404		11,113
Accruing 90 Days or Greater Past Due	225		129
Total Accruing Past Due	6,629		11,242
Non-accrual	26,099		39,239
Total loans	4,066,979		4,036,186
Commercial And Industrial [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	10,207,902		9,798,195
Accruing 30-89 Days Past Due	16,383		30,098
Accruing 90 Days or Greater Past Due	2,015		942
Total Accruing Past Due	18,398		31,040
Non-accrual	66,713		102,216
Total loans	10,293,013		9,931,451
Retail [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Current	3,856,021		3,558,743
Accruing 30-89 Days Past Due	23,950		27,094
Accruing 90 Days or Greater Past Due	2,190		2,680
Total Accruing Past Due	26,140		29,774
Non-accrual	52,007		59,716
Total loans	$ 3,934,168		$ 3,648,233

[1] Total before net deferred fees and costs of $30.8 million.

[2] Total before net deferred fees and costs of $28.9 million.