Calculation of Net Income (Loss) and Number of Shares Used to Compute Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net loss	$ (231,156)	$ (162,602)	$ (274,158)
Weighted average shares outstanding - basic and diluted	188,669	186,835	183,575
Net loss per share - basic and diluted	$ (1.23)	$ (0.87)	$ (1.49)