Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic:
Net income	$ 8,163	$ 8,092
Weighted-average common shares outstanding	14,455,527	14,679,619
Basic earnings per share	$ 0.56	$ 0.55
Diluted:
Net Income	$ 8,163	$ 8,092
Weighted-average common shares outstanding	14,455,527	14,679,619
Effect of dilutive restricted stock and stock appreciation rights	253,168	226,901
Weighted-average common shares outstanding assuming dilution	14,708,695	14,906,520
Diluted earnings per share	$ 0.55	$ 0.54