Earnings (Loss) Per Share - Securities Excluded from the Computation of Diluted Earnings (Loss) Per Common Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded in computation of diluted earning per share (in shares)	574	128
Restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded in computation of diluted earning per share (in shares)	203	59
Performance-based warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded in computation of diluted earning per share (in shares)	175	0