Parent Corporation Only Statements (Statement of Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Expenses
Total operating expenses	$ 99,095	$ 56,214	$ 46,135
Income (loss) before income taxes and undistributed income of subsidiaries	28,477	25,604	23,596
Income tax benefit	11,977	9,200	8,177
Net income	16,500	16,404	15,419
Parent [Member]
Income
Dividends from subsidiaries	4,500	8,000	8,625
Interest	(25)	(20)	(15)
Other	(222)	(134)	(113)
Operating Income (Loss)	4,747	8,154	8,753
Expenses
Other expenses	7,981	3,079	1,660
Total operating expenses	7,981	3,079	1,660
Income (loss) before income taxes and undistributed income of subsidiaries	(3,234)	5,075	7,093
Income tax benefit	(2,242)	(588)	(467)
Income (loss) before undistributed income of subsidiaries	(992)	5,663	7,560
Undistributed income of subsidiaries	17,492	10,741	7,859
Net income	$ 16,500	$ 16,404	$ 15,419