Loans And Allowance For Loan Losses (Schedule Of Impaired Loans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	$ 28,751	$ 35,108
Unpaid Principal Balance, With no related allowance recorded	40,794	78,312
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	26,433	50,030
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	220,745	266,692
Unpaid Principal Balance, With allowance recorded	222,393	270,004
Related Allowance, With allowance recorded	18,111	30,435
Average Recorded Investment, With allowance recorded	248,082	308,224
Interest Income Recognized, With allowance recorded	8,196	9,522
Recorded Investment	249,496	301,800
Unpaid Principal Balance	263,187	348,316
Related Allowance	18,111	30,435
Average Recorded Investment in Impaired Loans	274,515	358,254	$ 622,000
Interest Income Recognized	8,196	9,522
Home Equity Lines [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,051	1,030
Unpaid Principal Balance, With no related allowance recorded	1,051	1,030
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	1,045	573
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	9,638	9,575
Unpaid Principal Balance, With allowance recorded	9,638	9,575
Related Allowance, With allowance recorded	971	206
Average Recorded Investment, With allowance recorded	9,668	8,318
Interest Income Recognized, With allowance recorded	432	346
Recorded Investment	10,689	10,605
Unpaid Principal Balance	10,689	10,605
Related Allowance	971	206
Average Recorded Investment in Impaired Loans	10,713	8,891
Interest Income Recognized	432	346
Consumer Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	744	814
Unpaid Principal Balance, With no related allowance recorded	814	941
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	870	995
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	20,953	22,173
Unpaid Principal Balance, With allowance recorded	19,834	23,297
Related Allowance, With allowance recorded	673	651
Average Recorded Investment, With allowance recorded	20,993	26,044
Interest Income Recognized, With allowance recorded	1,014	1,229
Recorded Investment	21,697	22,987
Unpaid Principal Balance	20,648	24,238
Related Allowance	673	651
Average Recorded Investment in Impaired Loans	21,863	27,039
Interest Income Recognized	1,014	1,229
Credit Cards [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0	0
Unpaid Principal Balance, With no related allowance recorded	0	0
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	0	0
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	0	0
Unpaid Principal Balance, With allowance recorded	0	0
Related Allowance, With allowance recorded	0	0
Average Recorded Investment, With allowance recorded	0	0
Interest Income Recognized, With allowance recorded	0	0
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment in Impaired Loans	0	0
Interest Income Recognized	0	0
Other Retail Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0	0
Unpaid Principal Balance, With no related allowance recorded	0	0
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	0	0
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	5,140	4,651
Unpaid Principal Balance, With allowance recorded	5,140	4,651
Related Allowance, With allowance recorded	167	132
Average Recorded Investment, With allowance recorded	5,062	5,105
Interest Income Recognized, With allowance recorded	303	323
Recorded Investment	5,140	4,651
Unpaid Principal Balance	5,140	4,651
Related Allowance	167	132
Average Recorded Investment in Impaired Loans	5,062	5,105
Interest Income Recognized	303	323
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	3,490	20,109
Unpaid Principal Balance, With no related allowance recorded	10,975	57,525
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	9,803	28,068
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	87,920	137,849
Unpaid Principal Balance, With allowance recorded	87,926	138,419
Related Allowance, With allowance recorded	7,916	18,969
Average Recorded Investment, With allowance recorded	108,091	169,694
Interest Income Recognized, With allowance recorded	3,283	4,685
Recorded Investment	91,410	157,958
Unpaid Principal Balance	98,901	195,944
Related Allowance	7,916	18,969
Average Recorded Investment in Impaired Loans	117,894	197,762
Interest Income Recognized	3,283	4,685
Investment Properties [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	748	10,051
Unpaid Principal Balance, With no related allowance recorded	793	12,946
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	5,384	11,625
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	32,729	62,305
Unpaid Principal Balance, With allowance recorded	32,729	62,305
Related Allowance, With allowance recorded	2,267	10,070
Average Recorded Investment, With allowance recorded	42,836	73,211
Interest Income Recognized, With allowance recorded	1,699	2,131
Recorded Investment	33,477	72,356
Unpaid Principal Balance	33,522	75,251
Related Allowance	2,267	10,070
Average Recorded Investment in Impaired Loans	48,220	84,836
Interest Income Recognized	1,699	2,131
1-4 Family Properties [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,850	1,507
Unpaid Principal Balance, With no related allowance recorded	5,847	5,526
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	1,461	2,546
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	38,972	51,376
Unpaid Principal Balance, With allowance recorded	38,978	51,376
Related Allowance, With allowance recorded	4,754	6,184
Average Recorded Investment, With allowance recorded	47,806	61,690
Interest Income Recognized, With allowance recorded	1,098	1,618
Recorded Investment	40,822	52,883
Unpaid Principal Balance	44,825	56,902
Related Allowance	4,754	6,184
Average Recorded Investment in Impaired Loans	49,267	64,236
Interest Income Recognized	1,098	1,618
Land Acquisition [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	892	8,551
Unpaid Principal Balance, With no related allowance recorded	4,335	39,053
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	2,958	13,897
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	16,219	24,168
Unpaid Principal Balance, With allowance recorded	16,219	24,738
Related Allowance, With allowance recorded	895	2,715
Average Recorded Investment, With allowance recorded	17,449	34,793
Interest Income Recognized, With allowance recorded	486	936
Recorded Investment	17,111	32,719
Unpaid Principal Balance	20,554	63,791
Related Allowance	895	2,715
Average Recorded Investment in Impaired Loans	20,407	48,690
Interest Income Recognized	486	936
Commercial And Industrial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	23,466	13,155
Unpaid Principal Balance, With no related allowance recorded	27,954	18,816
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	14,715	20,394
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	97,094	92,444
Unpaid Principal Balance, With allowance recorded	99,855	94,062
Related Allowance, With allowance recorded	8,384	10,477
Average Recorded Investment, With allowance recorded	104,268	99,063
Interest Income Recognized, With allowance recorded	3,164	2,939
Recorded Investment	120,560	105,599
Unpaid Principal Balance	127,809	112,878
Related Allowance	8,384	10,477
Average Recorded Investment in Impaired Loans	118,983	119,457
Interest Income Recognized	3,164	2,939
Commercial, Financial and Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	17,958	4,393
Unpaid Principal Balance, With no related allowance recorded	20,577	7,606
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	6,321	5,737
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	43,386	42,914
Unpaid Principal Balance, With allowance recorded	45,913	44,374
Related Allowance, With allowance recorded	5,687	8,339
Average Recorded Investment, With allowance recorded	51,968	43,740
Interest Income Recognized, With allowance recorded	1,218	1,125
Recorded Investment	61,344	47,307
Unpaid Principal Balance	66,490	51,980
Related Allowance	5,687	8,339
Average Recorded Investment in Impaired Loans	58,289	49,477
Interest Income Recognized	1,218	1,125
Owner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	5,508	8,762
Unpaid Principal Balance, With no related allowance recorded	7,377	11,210
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	8,394	14,657
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	53,708	49,530
Unpaid Principal Balance, With allowance recorded	53,942	49,688
Related Allowance, With allowance recorded	2,697	2,138
Average Recorded Investment, With allowance recorded	52,300	55,323
Interest Income Recognized, With allowance recorded	1,946	1,814
Recorded Investment	59,216	58,292
Unpaid Principal Balance	61,319	60,898
Related Allowance	2,697	2,138
Average Recorded Investment in Impaired Loans	60,694	69,980
Interest Income Recognized	1,946	1,814
Retail [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,795	1,844
Unpaid Principal Balance, With no related allowance recorded	1,865	1,971
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	1,915	1,568
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With allowance recorded	35,731	36,399
Unpaid Principal Balance, With allowance recorded	34,612	37,523
Related Allowance, With allowance recorded	1,811	989
Average Recorded Investment, With allowance recorded	35,723	39,467
Interest Income Recognized, With allowance recorded	1,749	1,898
Recorded Investment	37,526	38,243
Unpaid Principal Balance	36,477	39,494
Related Allowance	1,811	989
Average Recorded Investment in Impaired Loans	37,638	41,035
Interest Income Recognized	$ 1,749	$ 1,898