Computation of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net loss available to common shareholders	$ (1,907)	$ (145,666)
Weighted average common shares outstanding - Basic (in shares)	39,658	38,945
Dilutive effect of stock-based awards (in shares)	0	0
Weighted average common shares outstanding - Diluted (in shares)	39,658	38,945
Earnings (loss) per common share - Basic (in dollars per share)	$ (0.05)	$ (3.74)
Earnings (loss) per common share - Diluted (in dollars per share)	$ (0.05)	$ (3.74)