Parent Company Only Condensed Financial Statements - Condensed Statements of Operations (Details) - USD ($) $ in Thousands	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, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Income [Abstract]
Dividends from subsidiaries									$ 226	$ 141	$ 273
Operating Expenses [Abstract]
Interest expense-subordinated debentures and notes									1,894	1,248	1,322
Interest expense-notes payable	$ 3,984	$ 3,463	$ 3,250	$ 3,032	$ 3,017	$ 3,174	$ 3,072	$ 3,106	13,729	12,369	14,386
Income tax benefit	(7,053)	(6,316)	(6,747)	(5,886)	(5,445)	(4,722)	(4,762)	(5,022)	(26,002)	(19,951)	(13,871)
Net income	$ 13,628	$ 11,832	$ 12,352	$ 11,025	$ 10,679	$ 9,709	$ 8,716	$ 9,346	48,837	38,450	27,173
Total comprehensive income									46,878	36,987	33,234
Parent [Member]
Operating Income [Abstract]
Dividends from subsidiaries									7,500	10,000	10,000
Other									491	249	225
Total income									7,991	10,249	10,225
Operating Expenses [Abstract]
Interest expense-subordinated debentures and notes									1,893	1,248	1,322
Interest expense-notes payable									53	144	193
Other expenses									5,526	3,823	4,402
Total expenses									7,472	5,215	5,917
Income before taxes and equity in undistributed earnings of subsidiaries									519	5,034	4,308
Income tax benefit									2,583	2,118	2,305
Net income									3,102	7,152	6,613
Equity in undistributed earnings of subsidiaries									45,735	31,298	20,560
Total comprehensive income									$ 48,837	$ 38,450	$ 27,173