Condensed Consolidated Statement of Stockholders' Equity - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balances at Dec. 31, 2017	$ 457,078	$ 275,059	$ 185,570	$ (3,551)
Net income	12,804		12,804
Other comprehensive loss, net of tax	(5,861)			(5,861)
Amortization of unearned compensation	61	61
Exercise of stock options	100	100
Stock option expense	82	82
Reclassification of tax adjustment on accumulated other comprehensive loss			766	(766)
Cash dividends on common stock	(3,848)		(3,848)
Ending Balances at Mar. 31, 2018	$ 460,416	$ 275,302	$ 195,292	$ (10,178)