Earnings (Loss) Per Share - Computation of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Loss	$ (16,051)	$ (18,502)	$ (48,827)	$ (343,573)
Average shares outstanding, basic (in shares)	30,449,286	29,849,753	30,252,670	29,708,673
Loss per share, basic (in usd per share)	$ (0.53)	$ (0.62)	$ (1.61)	$ (11.56)
Assumed exercise of stock options (in shares)	0	0	0	0
Unvested restricted stock and stock units (in shares)	0	0	0	0
Average shares outstanding, diluted (in shares)	30,449,286	29,849,753	30,252,670	29,708,673
Loss per share, diluted (in usd per share)	$ (0.53)	$ (0.62)	$ (1.61)	$ (11.56)