Earnings Per Share - Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
BASIC
Net income	$ 5,593	$ 6,993	$ 14,400	$ 5,846	$ 12,586	$ 20,246
Weighted-average common shares outstanding (in shares)	13,672		13,915		13,737	13,938
Basic earnings per share (in dollars per share)	$ 0.41		$ 1.03		$ 0.92	$ 1.45
DILUTED
Net income	$ 5,593	$ 6,993	$ 14,400	$ 5,846	$ 12,586	$ 20,246
Weighted-average common shares outstanding (in shares)	13,672		13,915		13,737	13,938
Dilutive effect of stock options, restricted stock and common stock warrants (in shares)	254		236		325	243
Weighted-average common shares outstanding on a diluted basis (in shares)	13,926		14,151		14,062	14,181
Diluted earnings per share (in dollars per share)	$ 0.40		$ 1.02		$ 0.89	$ 1.43