Loans and Allowance for Loan Losses (Schedule Of Impaired Loans) (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	$ 45,024,000		$ 45,024,000		$ 28,751,000
Recorded Investment, With allowance recorded	183,191,000		183,191,000		220,745,000
Recorded Investment	228,215,000		228,215,000		249,496,000
Unpaid Principal Balance, With no related allowance recorded	63,474,000		63,474,000		40,794,000
Unpaid Principal Balance, With allowance recorded	183,591,000		183,591,000		223,512,000
Unpaid Principal Balance	247,065,000		247,065,000		264,306,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	12,650,000		12,650,000		18,111,000
Related Allowance	12,650,000		12,650,000		18,111,000
Average Recorded Investment, With no related allowance recorded	42,423,000		37,962,000		26,433,000
Average Recorded Investment, With allowance recorded	190,109,000		195,829,000		248,082,000
Average Recorded Investment	232,532,000	$ 281,900,000	233,791,000	$ 290,300,000	274,515,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	1,834,000		3,523,000		8,196,000
Interest Income Recognized	1,834,000	$ 0	3,523,000		8,196,000
Total commercial real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	2,479,000		2,479,000		3,490,000
Recorded Investment, With allowance recorded	71,159,000		71,159,000		87,920,000
Recorded Investment	73,638,000		73,638,000		91,410,000
Unpaid Principal Balance, With no related allowance recorded	8,121,000		8,121,000		10,975,000
Unpaid Principal Balance, With allowance recorded	71,229,000		71,229,000		87,926,000
Unpaid Principal Balance	79,350,000		79,350,000		98,901,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	4,386,000		4,386,000		7,916,000
Related Allowance	4,386,000		4,386,000		7,916,000
Average Recorded Investment, With no related allowance recorded	2,503,000		2,819,000		9,803,000
Average Recorded Investment, With allowance recorded	71,763,000		73,951,000		108,091,000
Average Recorded Investment	74,266,000		76,770,000		117,894,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	682,000		1,282,000		3,286,000
Interest Income Recognized	682,000		1,282,000		3,286,000
Investment properties
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0		748,000
Recorded Investment, With allowance recorded	29,168,000		29,168,000		31,489,000
Recorded Investment	29,168,000		29,168,000		32,237,000
Unpaid Principal Balance, With no related allowance recorded	0		0		793,000
Unpaid Principal Balance, With allowance recorded	29,168,000		29,168,000		31,489,000
Unpaid Principal Balance	29,168,000		29,168,000		32,282,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	1,175,000		1,175,000		2,044,000
Related Allowance	1,175,000		1,175,000		2,044,000
Average Recorded Investment, With no related allowance recorded	0		246,000		2,013,000
Average Recorded Investment, With allowance recorded	29,264,000		29,575,000		42,659,000
Average Recorded Investment	29,264,000		29,821,000		44,672,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	306,000		597,000		1,436,000
Interest Income Recognized	306,000		597,000		1,436,000
1-4 family properties
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	253,000		253,000		643,000
Recorded Investment, With allowance recorded	15,879,000		15,879,000		23,642,000
Recorded Investment	16,132,000		16,132,000		24,285,000
Unpaid Principal Balance, With no related allowance recorded	2,582,000		2,582,000		2,939,000
Unpaid Principal Balance, With allowance recorded	15,893,000		15,893,000		23,649,000
Unpaid Principal Balance	18,475,000		18,475,000		26,588,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	448,000		448,000		769,000
Related Allowance	448,000		448,000		769,000
Average Recorded Investment, With no related allowance recorded	257,000		380,000		1,021,000
Average Recorded Investment, With allowance recorded	16,133,000		16,995,000		39,864,000
Average Recorded Investment	16,390,000		17,375,000		40,885,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	250,000		386,000		855,000
Interest Income Recognized	250,000		386,000		855,000
Land and development
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	2,226,000		2,226,000		2,099,000
Recorded Investment, With allowance recorded	26,112,000		26,112,000		32,789,000
Recorded Investment	28,338,000		28,338,000		34,888,000
Unpaid Principal Balance, With no related allowance recorded	5,539,000		5,539,000		7,243,000
Unpaid Principal Balance, With allowance recorded	26,168,000		26,168,000		32,788,000
Unpaid Principal Balance	31,707,000		31,707,000		40,031,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	2,763,000		2,763,000		5,103,000
Related Allowance	2,763,000		2,763,000		5,103,000
Average Recorded Investment, With no related allowance recorded	2,246,000		2,193,000		6,769,000
Average Recorded Investment, With allowance recorded	26,366,000		27,381,000		25,568,000
Average Recorded Investment	28,612,000		29,574,000		32,337,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	126,000		299,000		995,000
Interest Income Recognized	126,000		299,000		995,000
Total commercial and industrial
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	40,737,000		40,737,000		23,466,000
Recorded Investment, With allowance recorded	82,152,000		82,152,000		97,094,000
Recorded Investment	122,889,000		122,889,000		120,560,000
Unpaid Principal Balance, With no related allowance recorded	53,348,000		53,348,000		27,954,000
Unpaid Principal Balance, With allowance recorded	82,481,000		82,481,000		99,855,000
Unpaid Principal Balance	135,829,000		135,829,000		127,809,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	7,226,000		7,226,000		8,384,000
Related Allowance	7,226,000		7,226,000		8,384,000
Average Recorded Investment, With no related allowance recorded	38,112,000		33,339,000		14,715,000
Average Recorded Investment, With allowance recorded	87,277,000		89,269,000		104,268,000
Average Recorded Investment	125,389,000		122,608,000		118,983,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	772,000		1,461,000		3,161,000
Interest Income Recognized	772,000		1,461,000		3,161,000
Commercial, financial and agricultural
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	26,913,000		26,913,000		17,958,000
Recorded Investment, With allowance recorded	46,569,000		46,569,000		43,386,000
Recorded Investment	73,482,000		73,482,000		61,344,000
Unpaid Principal Balance, With no related allowance recorded	33,098,000		33,098,000		20,577,000
Unpaid Principal Balance, With allowance recorded	46,887,000		46,887,000		45,913,000
Unpaid Principal Balance	79,985,000		79,985,000		66,490,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	5,524,000		5,524,000		5,687,000
Related Allowance	5,524,000		5,524,000		5,687,000
Average Recorded Investment, With no related allowance recorded	26,202,000		22,956,000		6,321,000
Average Recorded Investment, With allowance recorded	48,959,000		46,455,000		51,968,000
Average Recorded Investment	75,161,000		69,411,000		58,289,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	436,000		787,000		1,215,000
Interest Income Recognized	436,000		787,000		1,215,000
Owner-occupied
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	13,824,000		13,824,000		5,508,000
Recorded Investment, With allowance recorded	35,583,000		35,583,000		53,708,000
Recorded Investment	49,407,000		49,407,000		59,216,000
Unpaid Principal Balance, With no related allowance recorded	20,250,000		20,250,000		7,377,000
Unpaid Principal Balance, With allowance recorded	35,594,000		35,594,000		53,942,000
Unpaid Principal Balance	55,844,000		55,844,000		61,319,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	1,702,000		1,702,000		2,697,000
Related Allowance	1,702,000		1,702,000		2,697,000
Average Recorded Investment, With no related allowance recorded	11,910,000		10,383,000		8,394,000
Average Recorded Investment, With allowance recorded	38,318,000		42,814,000		52,300,000
Average Recorded Investment	50,228,000		53,197,000		60,694,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	336,000		674,000		1,946,000
Interest Income Recognized	336,000		674,000		1,946,000
Total consumer
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,808,000		1,808,000		1,795,000
Recorded Investment, With allowance recorded	29,880,000		29,880,000		35,731,000
Recorded Investment	31,688,000		31,688,000		37,526,000
Unpaid Principal Balance, With no related allowance recorded	2,005,000		2,005,000		1,865,000
Unpaid Principal Balance, With allowance recorded	29,881,000		29,881,000		35,731,000
Unpaid Principal Balance	31,886,000		31,886,000		37,596,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	1,038,000		1,038,000		1,811,000
Related Allowance	1,038,000		1,038,000		1,811,000
Average Recorded Investment, With no related allowance recorded	1,808,000		1,804,000		1,915,000
Average Recorded Investment, With allowance recorded	31,069,000		32,609,000		35,723,000
Average Recorded Investment	32,877,000		34,413,000		37,638,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	380,000		780,000		1,749,000
Interest Income Recognized	380,000		780,000		1,749,000
Home equity lines
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,064,000		1,064,000		1,051,000
Recorded Investment, With allowance recorded	7,135,000		7,135,000		9,638,000
Recorded Investment	8,199,000		8,199,000		10,689,000
Unpaid Principal Balance, With no related allowance recorded	1,064,000		1,064,000		1,051,000
Unpaid Principal Balance, With allowance recorded	7,135,000		7,135,000		9,638,000
Unpaid Principal Balance	8,199,000		8,199,000		10,689,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	171,000		171,000		971,000
Related Allowance	171,000		171,000		971,000
Average Recorded Investment, With no related allowance recorded	1,064,000		1,060,000		1,045,000
Average Recorded Investment, With allowance recorded	7,680,000		8,197,000		9,668,000
Average Recorded Investment	8,744,000		9,257,000		10,713,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	229,000		465,000		432,000
Interest Income Recognized	229,000		465,000		432,000
Consumer mortgages
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	744,000		744,000		744,000
Recorded Investment, With allowance recorded	18,762,000		18,762,000		20,953,000
Recorded Investment	19,506,000		19,506,000		21,697,000
Unpaid Principal Balance, With no related allowance recorded	941,000		941,000		814,000
Unpaid Principal Balance, With allowance recorded	18,762,000		18,762,000		20,953,000
Unpaid Principal Balance	19,703,000		19,703,000		21,767,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	598,000		598,000		673,000
Related Allowance	598,000		598,000		673,000
Average Recorded Investment, With no related allowance recorded	744,000		744,000		870,000
Average Recorded Investment, With allowance recorded	19,009,000		19,720,000		20,993,000
Average Recorded Investment	19,753,000		20,464,000		21,863,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	92,000		183,000		1,014,000
Interest Income Recognized	92,000		183,000		1,014,000
Credit cards
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0		0
Recorded Investment, With allowance recorded	0		0		0
Recorded Investment	0		0		0
Unpaid Principal Balance, With no related allowance recorded	0		0		0
Unpaid Principal Balance, With allowance recorded	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	0		0		0
Related Allowance	0		0		0
Average Recorded Investment, With no related allowance recorded	0		0		0
Average Recorded Investment, With allowance recorded	0		0		0
Average Recorded Investment	0		0		0
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	0		0		0
Interest Income Recognized	0		0		0
Other consumer loans
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0		0		0
Recorded Investment, With allowance recorded	3,983,000		3,983,000		5,140,000
Recorded Investment	3,983,000		3,983,000		5,140,000
Unpaid Principal Balance, With no related allowance recorded	0		0		0
Unpaid Principal Balance, With allowance recorded	3,984,000		3,984,000		5,140,000
Unpaid Principal Balance	3,984,000		3,984,000		5,140,000
Related Allowance, With no related allowance recorded	0		0		0
Related Allowance, With allowance recorded	269,000		269,000		167,000
Related Allowance	269,000		269,000		167,000
Average Recorded Investment, With no related allowance recorded	0		0		0
Average Recorded Investment, With allowance recorded	4,380,000		4,692,000		5,062,000
Average Recorded Investment	4,380,000		4,692,000		5,062,000
Interest Income Recognized, With no related allowance recorded	0		0		0
Interest Income Recognized, With allowance recorded	59,000		132,000		303,000
Interest Income Recognized	$ 59,000		$ 132,000		$ 303,000