Parent Company Financial Information - Consolidated Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Dividends from subsidiary	$ 319	$ 334	$ 346
Income tax benefit	10,826	7,007	6,020
Net Income	15,249	16,301	15,039
Parent Company
Condensed Financial Statements, Captions [Line Items]
Dividends from subsidiary	6,000	16,000	11,000
Other income	588	117	80
Expenses	1,862	1,662	1,156
Income tax benefit	(581)	(526)	(366)
Income before equity in undistributed earnings of subsidiary	5,307	14,981	10,290
Equity in undistributed earnings of subsidiary	9,942	1,320	4,749
Net Income	$ 15,249	$ 16,301	$ 15,039