PARENT ONLY CONDENSED FINANCIAL STATEMENTS - Parent Only 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	Mar. 31, 2015	Jun. 30, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Expenses
Interest expense									$ 10,726	$ 8,385	$ 8,607
Salaries and benefits									64,327	57,741	54,132
Income before income tax									50,460	45,775	36,775
Income tax (benefit)									12,137	10,233	7,779
Net income	$ 11,744	$ 11,696	$ 6,117	$ 8,766	$ 9,108	$ 9,111	$ 7,663	$ 9,660	38,323	35,542	28,996
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									28,778	34,453	41,575
Parent Company
Income
Dividends from subsidiaries									43,100	28,900	24,275
Fees from subsidiaries									13,674	13,232	13,518
Other income									13	19	526
Total income									56,787	42,151	38,319
Expenses
Interest expense									1,876	1,264	1,286
Salaries and benefits									13,101	9,873	11,038
Professional fees									1,364	1,238	1,372
Other expenses									9,685	9,233	9,381
Total expenses									26,026	21,608	23,077
Income before income tax									30,761	20,543	15,242
Income tax (benefit)									(4,415)	(2,989)	(3,118)
Income before equity in undistributed income of subsidiaries									35,176	23,532	18,360
Equity in undistributed income (loss) of subsidiaries									3,147	12,010	10,636
Net income									38,323	35,542	28,996
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									$ 28,778	$ 34,453	$ 41,575