Earnings Per Share - Reconciliation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net income (loss)	$ (11,254)	$ 14,326	$ (14,142)	$ (19,698)	$ 7,400	$ (1,310)	$ 1,681	$ (6,051)	$ (30,768)	$ 1,720	$ (95,695)
Weighted average basic common shares outstanding									35,260	35,839	37,075
Effect of dilutive securities - stock options and awards										313
Total shares and dilutive securities									35,260	36,152	37,075
Basic income (loss) per common share	$ (0.33)	$ 0.41	$ (0.40)	$ (0.55)	$ 0.21	$ (0.04)	$ 0.05	$ (0.17)	$ (0.87)	$ 0.05	$ (2.58)
Diluted income (loss) per common share	$ (0.33)	$ 0.41	$ (0.40)	$ (0.55)	$ 0.21	$ (0.04)	$ 0.05	$ (0.17)	$ (0.87)	$ 0.05	$ (2.58)