Loans and Allowance for Loan Losses (Schedule Of Impaired Loans) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	$ 31,587,000		$ 35,108,000
Recorded Investment, With allowance recorded	266,198,000		266,692,000
Recorded Investment	297,785,000		301,800,000
Unpaid Principal Balance, With no related allowance recorded	49,998,000		78,312,000
Unpaid Principal Balance, With allowance recorded	272,786,000		270,004,000
Unpaid Principal Balance	322,784,000		348,316,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	32,973,000		30,435,000
Related Allowance	32,973,000		30,435,000
Average Recorded Investment, With no related allowance recorded	33,003,000		50,030,000
Average Recorded Investment, With allowance recorded	265,606,000		308,224,000
Average Recorded Investment	298,609,000	$ 427,400,000	358,254,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	1,984,000		9,522,000
Interest Income Recognized	1,984,000	$ 0	9,522,000
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	14,052,000		20,109,000
Recorded Investment, With allowance recorded	122,774,000		137,849,000
Recorded Investment	136,826,000		157,958,000
Unpaid Principal Balance, With no related allowance recorded	27,271,000		57,525,000
Unpaid Principal Balance, With allowance recorded	125,617,000		138,419,000
Unpaid Principal Balance	152,888,000		195,944,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	17,603,000		18,969,000
Related Allowance	17,603,000		18,969,000
Average Recorded Investment, With no related allowance recorded	16,869,000		28,068,000
Average Recorded Investment, With allowance recorded	130,537,000		169,694,000
Average Recorded Investment	147,406,000		197,762,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	901,000		4,685,000
Interest Income Recognized	901,000		4,685,000
Investment Properties [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	8,557,000		10,051,000
Recorded Investment, With allowance recorded	53,449,000		62,305,000
Recorded Investment	62,006,000		72,356,000
Unpaid Principal Balance, With no related allowance recorded	11,192,000		12,946,000
Unpaid Principal Balance, With allowance recorded	53,475,000		62,305,000
Unpaid Principal Balance	64,667,000		75,251,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	9,158,000		10,070,000
Related Allowance	9,158,000		10,070,000
Average Recorded Investment, With no related allowance recorded	9,359,000		11,625,000
Average Recorded Investment, With allowance recorded	58,015,000		73,211,000
Average Recorded Investment	67,374,000		84,836,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	656,000		2,131,000
Interest Income Recognized	656,000		2,131,000
1-4 Family Properties [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,504,000		1,507,000
Recorded Investment, With allowance recorded	49,048,000		51,376,000
Recorded Investment	50,552,000		52,883,000
Unpaid Principal Balance, With no related allowance recorded	5,525,000		5,526,000
Unpaid Principal Balance, With allowance recorded	49,048,000		51,376,000
Unpaid Principal Balance	54,573,000		56,902,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	5,899,000		6,184,000
Related Allowance	5,899,000		6,184,000
Average Recorded Investment, With no related allowance recorded	1,505,000		2,546,000
Average Recorded Investment, With allowance recorded	49,434,000		61,690,000
Average Recorded Investment	50,939,000		64,236,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	117,000		1,618,000
Interest Income Recognized	117,000		1,618,000
Land Acquisition [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	3,991,000		8,551,000
Recorded Investment, With allowance recorded	20,277,000		24,168,000
Recorded Investment	24,268,000		32,719,000
Unpaid Principal Balance, With no related allowance recorded	10,554,000		39,053,000
Unpaid Principal Balance, With allowance recorded	23,094,000		24,738,000
Unpaid Principal Balance	33,648,000		63,791,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	2,546,000		2,715,000
Related Allowance	2,546,000		2,715,000
Average Recorded Investment, With no related allowance recorded	6,005,000		13,897,000
Average Recorded Investment, With allowance recorded	23,088,000		34,793,000
Average Recorded Investment	29,093,000		48,690,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	128,000		936,000
Interest Income Recognized	128,000		936,000
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	15,677,000		13,155,000
Recorded Investment, With allowance recorded	107,880,000		92,444,000
Recorded Investment	123,557,000		105,599,000
Unpaid Principal Balance, With no related allowance recorded	19,618,000		18,816,000
Unpaid Principal Balance, With allowance recorded	111,625,000		94,062,000
Unpaid Principal Balance	131,243,000		112,878,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	14,033,000		10,477,000
Related Allowance	14,033,000		10,477,000
Average Recorded Investment, With no related allowance recorded	14,285,000		20,394,000
Average Recorded Investment, With allowance recorded	98,951,000		99,063,000
Average Recorded Investment	113,236,000		119,457,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	633,000		2,939,000
Interest Income Recognized	633,000		2,939,000
Commercial, Financial and Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	6,185,000		4,393,000
Recorded Investment, With allowance recorded	58,312,000		42,914,000
Recorded Investment	64,497,000		47,307,000
Unpaid Principal Balance, With no related allowance recorded	8,585,000		7,606,000
Unpaid Principal Balance, With allowance recorded	61,865,000		44,374,000
Unpaid Principal Balance	70,450,000		51,980,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	12,399,000		8,339,000
Related Allowance	12,399,000		8,339,000
Average Recorded Investment, With no related allowance recorded	5,715,000		5,737,000
Average Recorded Investment, With allowance recorded	49,547,000		43,740,000
Average Recorded Investment	55,262,000		49,477,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	189,000		1,125,000
Interest Income Recognized	189,000		1,125,000
Owner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	9,492,000		8,762,000
Recorded Investment, With allowance recorded	49,568,000		49,530,000
Recorded Investment	59,060,000		58,292,000
Unpaid Principal Balance, With no related allowance recorded	11,033,000		11,210,000
Unpaid Principal Balance, With allowance recorded	49,760,000		49,688,000
Unpaid Principal Balance	60,793,000		60,898,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	1,634,000		2,138,000
Related Allowance	1,634,000		2,138,000
Average Recorded Investment, With no related allowance recorded	8,570,000		14,657,000
Average Recorded Investment, With allowance recorded	49,404,000		55,323,000
Average Recorded Investment	57,974,000		69,980,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	444,000		1,814,000
Interest Income Recognized	444,000		1,814,000
Retail [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,858,000		1,844,000
Recorded Investment, With allowance recorded	35,544,000		36,399,000
Recorded Investment	37,402,000		38,243,000
Unpaid Principal Balance, With no related allowance recorded	3,109,000		1,971,000
Unpaid Principal Balance, With allowance recorded	35,544,000		37,523,000
Unpaid Principal Balance	38,653,000		39,494,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	1,337,000		989,000
Related Allowance	1,337,000		989,000
Average Recorded Investment, With no related allowance recorded	1,849,000		1,568,000
Average Recorded Investment, With allowance recorded	36,118,000		39,467,000
Average Recorded Investment	37,967,000		41,035,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	450,000		1,898,000
Interest Income Recognized	450,000		1,898,000
Home Equity Lines [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,044,000		1,030,000
Recorded Investment, With allowance recorded	9,772,000		9,575,000
Recorded Investment	10,816,000		10,605,000
Unpaid Principal Balance, With no related allowance recorded	1,044,000		1,030,000
Unpaid Principal Balance, With allowance recorded	9,772,000		9,575,000
Unpaid Principal Balance	10,816,000		10,605,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	165,000		206,000
Related Allowance	165,000		206,000
Average Recorded Investment, With no related allowance recorded	1,035,000		573,000
Average Recorded Investment, With allowance recorded	9,618,000		8,318,000
Average Recorded Investment	10,653,000		8,891,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	116,000		346,000
Interest Income Recognized	116,000		346,000
Consumer Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	814,000		814,000
Recorded Investment, With allowance recorded	21,224,000		22,173,000
Recorded Investment	22,038,000		22,987,000
Unpaid Principal Balance, With no related allowance recorded	2,065,000		941,000
Unpaid Principal Balance, With allowance recorded	21,224,000		23,297,000
Unpaid Principal Balance	23,289,000		24,238,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	1,029,000		651,000
Related Allowance	1,029,000		651,000
Average Recorded Investment, With no related allowance recorded	814,000		995,000
Average Recorded Investment, With allowance recorded	21,821,000		26,044,000
Average Recorded Investment	22,635,000		27,039,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	262,000		1,229,000
Interest Income Recognized	262,000		1,229,000
Credit Card Receivable [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0
Recorded Investment, With allowance recorded	0		0
Recorded Investment	0		0
Unpaid Principal Balance, With no related allowance recorded	0		0
Unpaid Principal Balance, With allowance recorded	0		0
Unpaid Principal Balance	0		0
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	0		0
Related Allowance	0		0
Average Recorded Investment, With no related allowance recorded	0		0
Average Recorded Investment, With allowance recorded	0		0
Average Recorded Investment	0		0
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	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
Recorded Investment, With allowance recorded	4,548,000		4,651,000
Recorded Investment	4,548,000		4,651,000
Unpaid Principal Balance, With no related allowance recorded	0		0
Unpaid Principal Balance, With allowance recorded	4,548,000		4,651,000
Unpaid Principal Balance	4,548,000		4,651,000
Related Allowance, With no related allowance recorded	0		0
Related Allowance, With allowance recorded	143,000		132,000
Related Allowance	143,000		132,000
Average Recorded Investment, With no related allowance recorded	0		0
Average Recorded Investment, With allowance recorded	4,679,000		5,105,000
Average Recorded Investment	4,679,000		5,105,000
Interest Income Recognized, With no related allowance recorded	0		0
Interest Income Recognized, With allowance recorded	72,000		323,000
Interest Income Recognized	$ 72,000		$ 323,000