Earnings Per Share - Computation of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator (both basic and diluted):
Net loss	$ (30,531)	$ (38,626)
Denominator:
Denominator for basic loss per share (in shares)	26,336,044	25,999,383
Basic loss per common share (in dollars per share)	$ (1.16)	$ (1.49)
Diluted loss per common share (in dollars per share)	$ (1.16)	$ (1.49)