Net Loss Per Share - Summary of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net loss	$ (179,958)	$ (168,221)	$ (163,406)	$ (122,918)	$ (16,978)	$ (74,598)	$ (511,585)	$ (214,494)
Denominator:
Weighted average common stock outstanding —basic	51,704,687			46,706,770			50,496,489	45,866,676
Dilutive effect of shares of common stock equivalents resulting from common stock options and restricted stock units	0			0			0	0
Weighted average common stock outstanding —diluted	51,704,687			46,706,770			50,496,489	45,866,676
Net loss per share—basic and diluted	$ (3.48)			$ (2.63)			$ (10.13)	$ (4.68)

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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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible preferred stock using the if-converted method.

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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 average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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