Earnings Per Share - Reconciliation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator
Net loss - basic and diluted	$ (5,998)	$ (26,244)	$ (11,360)	$ (38,392)
Denominator
Weighted average common shares outstanding - basic (in shares)	91,145	89,981	90,924	89,813
Dilutive effect of stock options and restricted stock awards (in shares)	0	0	0	0
Dilutive effect of Convertible Notes (in shares)	0	0	0	0
Weighted average common shares outstanding - diluted (in shares)	91,145	89,981	90,924	89,813
Net loss per common share
Basic (in dollars per share)	$ (0.07)	$ (0.29)	$ (0.12)	$ (0.43)
Diluted (in dollars per share)	$ (0.07)	$ (0.29)	$ (0.12)	$ (0.43)