Earnings Per Share - Reconciliation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator
Net income (loss) - basic and diluted	$ (26,244)	$ 4,306	$ (38,392)	$ 5,588
Denominator
Weighted average common shares outstanding - basic (in shares)	89,981	89,806	89,813	89,958
Dilutive effect of stock options and restricted stock awards (in shares)	0	1,900	0	2,082
Dilutive effect of Convertible Notes (in shares)	0	0	0	0
Weighted average common shares outstanding - diluted (in shares)	89,981	91,706	89,813	92,040
Net income (loss) per common share
Basic (in dollars per share)	$ (0.29)	$ 0.05	$ (0.43)	$ 0.06
Diluted (in dollars per share)	$ (0.29)	$ 0.05	$ (0.43)	$ 0.06
Stock options and restricted stock awards (in shares)	5,067	1,707	4,951	1,710