Net Loss Per Share - Basic and Diluted Income (Loss) Per Common Share Computation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator:
Net loss used for calculation of basic and diluted EPS	$ (43,244)	$ (40,654)	$ (92,780)	$ (78,310)
Denominator:
Weighted average shares outstanding, basic (in shares)	42,153,813	35,784,804	39,559,599	35,373,799
Effect of dilutive securities:
Stock options and restricted stock units (in shares)	0	0	0	0
Weighted average shares outstanding, diluted	42,153,813	35,784,804	39,559,599	35,373,799
Basic and diluted net loss per common share (in usd per share)	$ (1.03)	$ (1.14)	$ (2.35)	$ (2.21)

The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

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