Common Stock and Loss Per Share - Reconciliation of Numerators and Denominators of Basic and Diluted Loss Per Share Computation (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Basic and diluted loss per share
Net loss available to common stockholders (numerator)	$ (529,158)	$ (263,190)	$ (110,328)
Weighted-average common shares outstanding (denominator)	35,973	37,578	37,631
Basic and diluted loss per common and common equivalent share	$ (14.71)	$ (7.00)	$ (2.93)