Parent Company Only Financial Statements - Income Statements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income
Other interest income	$ 611	$ 468	$ 444
Net interest income	110,950	93,872	83,376
Expenses
Interest expense	9,544	8,910	9,513
Other noninterest expense	22,212	17,982	15,037
Net income	40,591	47,856	32,462
Parent Company
Income
Other interest income	33	33	32
Interest income from Bank subsidiary	95	121	118
Gain on sale of investments	417
Dividend income from Bank subsidiary	14,875	25,105	18,155
Earnings from Bank subsidiary	26,859	23,879	15,429
Net interest income	42,279	49,138	33,734
Expenses
Interest expense	1,393	1,298	1,278
Salaries, legal and professional fees	315	3	3
Other noninterest expense	168	59	69
Federal and state income tax benefit	(188)	(78)	(78)
Total expenses	1,688	1,282	1,272
Net income	$ 40,591	$ 47,856	$ 32,462