Earnings Per Share - Summary (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Calculation of basic and diluted earnings per common share from continuing operations
Earnings (loss) from continuing operations	$ (111,996)	$ (23,272)	$ 286,922
Less: Distributed and undistributed earnings allocated to unvested stock	(517)	(453)	(1,038)
Earnings (loss) from continuing operations available to common shareholders	$ (112,513)	$ (23,725)	$ 285,884
Weighted average common shares outstanding— Basic (in shares)	52,362	52,348	52,390
Effect of dilutive equity awards (in shares)	0	0	307
Weighted average common shares outstanding— Diluted (in shares)	52,362	52,348	52,697
Earnings (loss) from continuing operations per common share — Basic (in dollars per share)	$ (2.15)	$ (0.45)	$ 5.46
Earnings (loss) from continuing operations per common share - Diluted (in dollars per share)	$ (2.15)	$ (0.45)	$ 5.43
Anti-dilutive equity awards not included in diluted EPS (in shares)	3,504	2,458	1,330