Loans and Allowance for Loan Losses, Allowance for Credit Losses (Details) - USD ($)		3 Months Ended												12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	$ 58,980,475	$ 65,432,354
Troubled debt restructurings classified as impaired loans																	15,000,000	8,100,000
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					$ 65,432,000				$ 67,359,000				$ 67,970,000	$ 65,432,000	$ 67,359,000	$ 67,970,000
Charged-off loans														(31,112,118)	(21,148,034)	(7,702,661)
Recovery of previously charged-off loans														6,332,000	10,033,000	3,457,000
Provision for loan losses		$ 3,046,000	$ 6,108,000	$ 5,280,000	3,894,000	$ 5,459,000	$ 2,228,000	$ 1,186,000	315,000	$ 2,041,000	$ 851,000	$ 254,000	488,000	18,328,058	9,188,497	3,634,660
Ending Balance		58,980,000				65,432,000				67,359,000				58,980,000	65,432,000	67,359,000
Financing Receivable, Individually Evaluated for Impairment																	33,750,000	25,313,000	$ 25,116,000
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment																	1,092,000	5,165,000	2,885,000
Financing Receivable, Collectively Evaluated for Impairment																	8,407,340,000	6,505,788,000	4,564,911,000
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment																	57,014,000	59,730,000	61,202,000
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		58,980,000			65,432,000	65,432,000			67,359,000	67,359,000			67,970,000	65,432,000	67,359,000	67,359,000	58,980,000	65,432,000	67,359,000
Loans and Leases Receivable, Net of Deferred Income																	8,449,924,736	6,543,235,381	4,590,027,000
Loans and other extensions of credit granted to directors, executive officers, and their related entities																	22,600,000	14,500,000
Amount drawn from loans and other extensions of credit granted																	14,800,000	11,400,000
Mortgage loans held-for-sale																	47,710,120	47,930,253
Gain loss on sale of loans held for sale														15,754,473	7,668,960	5,630,371
Receivables Acquired with Deteriorated Credit Quality [Member]
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					0				0					0	0
Ending Balance		0				0				0				0	0	0
Financing Receivable, Acquired with Deteriorated Credit Quality																	8,835,000	12,134,000	0
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		0			0	0			0	0				0	0	0	0	0	0
Commercial Real Estate - Mortgage [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	13,655,000	15,513,000
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					15,513,000				22,202,000				21,372,000	15,513,000	22,202,000	21,372,000
Charged-off loans														(276,000)	(384,000)	(875,000)
Recovery of previously charged-off loans														208,000	85,000	538,000
Provision for loan losses														(1,790,000)	(6,390,000)	1,167,000
Ending Balance		13,655,000				15,513,000				22,202,000				13,655,000	15,513,000	22,202,000
Financing Receivable, Individually Evaluated for Impairment																	2,750,000	2,420,000	4,313,000
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment																	60,000	61,000	108,000
Financing Receivable, Collectively Evaluated for Impairment																	3,188,362,000	2,269,439,000	1,539,778,000
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment																	13,595,000	15,452,000	22,094,000
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		13,655,000			15,513,000	15,513,000			22,202,000	22,202,000			21,372,000	15,513,000	15,513,000	22,202,000	13,655,000	15,513,000	22,202,000
Loans and Leases Receivable, Net of Deferred Income																	3,193,496,000	2,275,483,000	1,544,091,000
Commercial Real Estate - Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					0				0					0	0
Ending Balance		0				0				0				0	0	0
Financing Receivable, Acquired with Deteriorated Credit Quality																	2,384,000	3,624,000	0
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		0			0	0			0	0				0	0	0	0	0	0
Consumer Real Estate - Mortgage [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	6,564,000	7,220,000
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					7,220,000				5,424,000				8,355,000	7,220,000	5,424,000	8,355,000
Charged-off loans														(788,000)	(365,000)	(1,621,000)
Recovery of previously charged-off loans														546,000	874,000	671,000
Provision for loan losses														(414,000)	1,287,000	(1,981,000)
Ending Balance		6,564,000				7,220,000				5,424,000				6,564,000	7,220,000	5,424,000
Financing Receivable, Individually Evaluated for Impairment																	8,941,000	8,986,000	8,384,000
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment																	690,000	1,111,000	1,461,000
Financing Receivable, Collectively Evaluated for Impairment																	1,174,456,000	1,033,479,000	712,774,000
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment																	5,874,000	6,109,000	3,963,000
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		6,564,000			7,220,000	7,220,000			5,424,000	5,424,000			8,355,000	7,220,000	5,424,000	5,424,000	6,564,000	7,220,000	5,424,000
Loans and Leases Receivable, Net of Deferred Income																	1,185,917,000	1,046,517,000	721,158,000
Consumer Real Estate - Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					0				0					0	0
Ending Balance		0				0				0				0	0	0
Financing Receivable, Acquired with Deteriorated Credit Quality																	2,520,000	4,052,000	0
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		0			0	0			0	0				0	0	0	0	0	0
Construction and Land Development [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	3,624,000	2,903,000
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					2,903,000				5,724,000				7,235,000	2,903,000	5,724,000	7,235,000
Charged-off loans														(231,000)	(190,000)	(301,000)
Recovery of previously charged-off loans														545,000	1,479,000	277,000
Provision for loan losses														407,000	(4,110,000)	(1,487,000)
Ending Balance		3,624,000				2,903,000				5,724,000				3,624,000	2,903,000	5,724,000
Financing Receivable, Individually Evaluated for Impairment																	3,212,000	3,689,000	5,609,000
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment																	20,000	12,000	169,000
Financing Receivable, Collectively Evaluated for Impairment																	906,053,000	740,090,000	316,857,000
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment																	3,604,000	2,891,000	5,555,000
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		3,624,000			2,903,000	2,903,000			5,724,000	5,724,000			7,235,000	2,903,000	2,903,000	5,724,000	3,624,000	2,903,000	5,724,000
Loans and Leases Receivable, Net of Deferred Income																	912,673,000	747,697,000	322,466,000
Construction and Land Development [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					0				0					0	0
Ending Balance		0				0				0				0	0	0
Financing Receivable, Acquired with Deteriorated Credit Quality																	3,408,000	3,918,000	0
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		0			0	0			0	0				0	0	0	0	0	0
Commercial and Industrial [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	24,743,000	23,643,000
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					23,643,000				29,167,000				25,134,000	23,643,000	29,167,000	25,134,000
Charged-off loans														(5,801,000)	(2,207,000)	(3,095,000)
Recovery of previously charged-off loans														2,138,000	1,730,000	1,484,000
Provision for loan losses														4,763,000	(5,047,000)	5,644,000
Ending Balance		24,743,000				23,643,000				29,167,000				24,743,000	23,643,000	29,167,000
Financing Receivable, Individually Evaluated for Impairment																	18,331,000	5,288,000	5,382,000
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment																	95,000	974,000	838,000
Financing Receivable, Collectively Evaluated for Impairment																	2,872,856,000	2,222,714,000	1,779,347,000
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment																	24,648,000	22,669,000	28,329,000
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		24,743,000			23,643,000	23,643,000			29,167,000	29,167,000			25,134,000	23,643,000	23,643,000	29,167,000	24,743,000	23,643,000	29,167,000
Loans and Leases Receivable, Net of Deferred Income																	2,891,710,000	2,228,542,000	1,784,729,000
Commercial and Industrial [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					0				0					0	0
Ending Balance		0				0				0				0	0	0
Financing Receivable, Acquired with Deteriorated Credit Quality																	523,000	540,000	0
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		0			0	0			0	0				0	0	0	0	0	0
Consumer and Other [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	9,520,000	15,616,000
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					15,616,000				1,570,000				1,632,000	15,616,000	1,570,000	1,632,000
Charged-off loans														(24,016,000)	(18,002,000)	(1,811,000)
Recovery of previously charged-off loans														2,895,000	5,865,000	487,000
Provision for loan losses														15,025,000	26,183,000	1,262,000
Ending Balance		9,520,000				15,616,000				1,570,000				9,520,000	15,616,000	1,570,000
Financing Receivable, Individually Evaluated for Impairment																	516,000	4,930,000	1,428,000
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment																	227,000	3,007,000	309,000
Financing Receivable, Collectively Evaluated for Impairment																	265,613,000	240,066,000	216,155,000
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment																	9,293,000	12,609,000	1,261,000
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		9,520,000			15,616,000	15,616,000			1,570,000	1,570,000			1,632,000	15,616,000	15,616,000	1,570,000	9,520,000	15,616,000	1,570,000
Loans and Leases Receivable, Net of Deferred Income																	266,129,000	244,996,000	217,583,000
Consumer and Other [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					0				0					0	0
Ending Balance		0				0				0				0	0	0
Financing Receivable, Acquired with Deteriorated Credit Quality																	0	0	0
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		0			0	0			0	0				0	0	0	0	0	0
Unallocated [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	874,000	537,000
Changes in allowance for loan losses [Roll Forward]
Beginning Balance					537,000				3,272,000				4,242,000	537,000	3,272,000	4,242,000
Charged-off loans														0	0	0
Recovery of previously charged-off loans														0	0	0
Provision for loan losses														337,000	(2,735,000)	(970,000)
Ending Balance		874,000				537,000				3,272,000				874,000	537,000	3,272,000
Financing Receivable, Allowance for Credit Losses, Acquired with Deteriorated Credit Quality		$ 874,000			$ 537,000	$ 537,000			$ 3,272,000	$ 3,272,000			$ 4,242,000	$ 537,000	$ 537,000	$ 4,242,000	874,000	537,000	$ 3,272,000
Impaired Loans [Member]
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	42,585,000	37,447,000
Impaired Loans [Member] | Commercial Real Estate - Mortgage [Member]
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	5,134,000	6,044,000
Impaired Loans [Member] | Consumer Real Estate - Mortgage [Member]
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	11,461,000	13,038,000
Impaired Loans [Member] | Construction and Land Development [Member]
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	6,620,000	7,607,000
Impaired Loans [Member] | Commercial and Industrial [Member]
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	18,854,000	5,828,000
Impaired Loans [Member] | Consumer and Other [Member]
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	516,000	4,930,000
Accruing Loans [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	57,014,000	59,730,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	8,407,340,000	6,505,788,000
Accruing Loans [Member] | Commercial Real Estate - Mortgage [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	13,595,000	15,452,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	3,188,362,000	2,269,439,000
Accruing Loans [Member] | Consumer Real Estate - Mortgage [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	5,874,000	6,109,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	1,174,456,000	1,033,479,000
Accruing Loans [Member] | Construction and Land Development [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	3,604,000	2,891,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	906,053,000	740,090,000
Accruing Loans [Member] | Commercial and Industrial [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	24,648,000	22,669,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	2,872,856,000	2,222,714,000
Accruing Loans [Member] | Consumer and Other [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	9,293,000	12,609,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income																	265,613,000	240,066,000
Accruing Loans [Member] | Unallocated [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	0	0
Nonaccrual Loans [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	1,071,000	3,669,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[1]																27,577,000	29,359,000
Nonaccrual Loans [Member] | Commercial Real Estate - Mortgage [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	59,000	20,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[1]																4,921,000	5,821,000
Nonaccrual Loans [Member] | Consumer Real Estate - Mortgage [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	688,000	616,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[1]																8,073,000	9,346,000
Nonaccrual Loans [Member] | Construction and Land Development [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	20,000	12,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[1]																6,613,000	7,607,000
Nonaccrual Loans [Member] | Commercial and Industrial [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	77,000	19,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[1]																7,495,000	1,683,000
Nonaccrual Loans [Member] | Consumer and Other [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	227,000	3,002,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[1]																475,000	4,902,000
Nonaccrual Loans [Member] | Unallocated [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses																	0	0
Troubled Debt Restructurings [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses	[2]																21,000	1,496,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[3]																15,008,000	8,088,000
Troubled Debt Restructurings [Member] | Commercial Real Estate - Mortgage [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses	[2]																1,000	41,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[3]																213,000	223,000
Troubled Debt Restructurings [Member] | Consumer Real Estate - Mortgage [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses	[2]																2,000	495,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[3]																3,388,000	3,692,000
Troubled Debt Restructurings [Member] | Construction and Land Development [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses	[2]																0	0
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[3]																7,000	0
Troubled Debt Restructurings [Member] | Commercial and Industrial [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses	[2]																18,000	955,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[3]																11,359,000	4,145,000
Troubled Debt Restructurings [Member] | Consumer and Other [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses	[2]																0	5,000
Changes in allowance for loan losses [Roll Forward]
Loans and Leases Receivable, Net of Deferred Income	[3]																41,000	28,000
Troubled Debt Restructurings [Member] | Unallocated [Member]
Allowance allocation by loan classification for accruing and impaired loans [Abstract]
Total Allowance for Loan Losses	[2]																$ 0	$ 0

[1] Included in nonaccrual loans at December 31, 2016 and 2015 are $8.8 million and $12.1 million, respectively, in loans acquired with deteriorated credit quality and accounted for as purchase credit impaired.

[2] Troubled debt restructurings of $15.0 million and $8.1 million as of December 31, 2016 and 2015, respectively, are classified as impaired loans pursuant to U.S. GAAP; however, these loans continue to accrue interest at contractual rates.

[3] Troubled debt restructurings are presented as an impaired loan; however, they continue to accrue interest at contractual rates.