Earnings (Loss) Per Share - Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
BASIC
Net income (loss)	$ 6,168	$ 14,400	$ 5,846	$ 2,669	$ (5,061)	$ (1,005)	$ 26,414	$ (3,397)
Weighted-average common shares outstanding (in shares)	13,928			13,894			13,935	13,861
Basic earnings (loss) per share (in dollars per share)	$ 0.44			$ 0.19			$ 1.90	$ (0.25)
DILUTED
Net income (loss)	$ 6,168	$ 14,400	$ 5,846	$ 2,669	$ (5,061)	$ (1,005)	$ 26,414	$ (3,397)
Weighted-average common shares outstanding (in shares)	13,928			13,894			13,935	13,861
Dilutive effect of stock options, restricted stock and common stock warrants (in shares)	277			276			254	0
Weighted-average common shares outstanding on a diluted basis (in shares)	14,205			14,170			14,189	13,861
Diluted earnings (loss) per share (in dollars per share)	$ 0.43			$ 0.19			$ 1.86	$ (0.25)