Earnings (Loss) Per Share - Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
BASIC
Net income (loss)	$ 7,027	$ 2,669	$ (5,061)	$ (1,005)	$ (11,107)	$ 959	$ 22,659	$ (587)	$ 3,630	$ 11,924	$ (10,323)
Weighted-average common shares outstanding (in shares)									13,879	13,948	14,351
Basic earnings (loss) per share (in dollars per share)	$ 0.50	$ 0.19	$ (0.37)	$ (0.07)	$ (0.80)	$ 0.07	$ 1.61	$ (0.04)	$ 0.26	$ 0.85	$ (0.72)
DILUTED
Net income (loss)	$ 7,027	$ 2,669	$ (5,061)	$ (1,005)	$ (11,107)	$ 959	$ 22,659	$ (587)	$ 3,630	$ 11,924	$ (10,323)
Weighted-average common shares outstanding (in shares)									13,879	13,948	14,351
Dilutive effect of stock options, restricted stock and common stock warrants (in shares)									230	112	0
Weighted-average common shares outstanding on a diluted basis (in shares)									14,109	14,060	14,351
Diluted earnings (loss) per share (in dollars per share)	$ 0.49	$ 0.19	$ (0.37)	$ (0.07)	$ (0.80)	$ 0.07	$ 1.60	$ (0.04)	$ 0.26	$ 0.85	$ (0.72)