Earnings (Loss) Per Share - Reconciliation of basic and diluted EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net (loss) income	$ (95,304)	$ 68,271	$ (41,276)
Weighted average shares:
Basic shares (in shares)	37,325	40,465	41,248
Effect of dilutive securities - options and warrants outstanding (in shares)	0	1,300	0
Diluted shares (in shares)	37,325	41,765	41,248
Net income (loss) per share - basic (in usd per share)	$ (2.55)	$ 1.69	$ (1.00)
Net income (loss) per share - diluted (in usd per share)	$ (2.55)	$ 1.63	$ (1.00)