Parent Only Condensed Financial Statements - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 100,383	$ 38,568	$ 94,617	$ 77,328
Total assets	1,661,655	1,443,323
Liabilities:
Junior subordinated debentures due to subsidiary grantor trust	5,155	5,155
Total liabilities	1,452,096	1,279,290
Shareholders’ equity:
Preferred stock, Series C	0	0
Common stock	103,314	71,645
Retained earnings	103,419	92,904
Accumulated other comprehensive (loss) income, net of tax	2,826	(516)
Total shareholders' equity	209,559	164,033	139,323	131,045
Total liabilities and shareholders' equity	1,661,655	1,443,323
Parent Company
ASSETS
Cash and cash equivalents	3,296	887	$ 584	$ 368
Investment in Bank subsidiary	210,816	167,666
Other assets	750	790
Total assets	214,862	169,343
Liabilities:
Junior subordinated debentures due to subsidiary grantor trust	5,155	5,155
Other liabilities	148	155
Total liabilities	5,303	5,310
Shareholders’ equity:
Common stock	103,314	71,645
Retained earnings	103,419	92,904
Accumulated other comprehensive (loss) income, net of tax	2,826	(516)
Total shareholders' equity	209,559	164,033
Total liabilities and shareholders' equity	$ 214,862	$ 169,343