Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net loss		$ (76,643)	$ (35,363)
Weighted-average number of shares of common stock and common stock equivalents outstanding:
Weighted-average number of shares of common stock outstanding for computing basic loss earnings per share		71,731	64,631
Dilutive effect of outstanding stock awards and stock options after application of the treasury stock method	[1]	0	0
Weighted-average number of shares of common stock and dilutive common stock equivalents outstanding for computing diluted loss per share		71,731	64,631
Net loss per share - basic and diluted		$ (1.07)	$ (0.55)

[1] For the three months ended March 31, 2019 and 2018, stock options, RSAs, RSUs, stock appreciation rights to purchase 9.8 million and 9.9 million shares of the Company’s common stock, respectively, were excluded from the net loss per share calculation as their effect would have been anti-dilutive.