Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Net income (loss) from continuing operations	$ 42,062	$ (37,327)
Net income from discontinued operations	0	6,216
Net income (loss)	$ 42,062	$ (31,111)
Weighted-average shares used to calculate basic EPS	72,773	68,132
Effect of dilutive securities:
Employee equity awards	594	0
Weighted-average shares used to calculate diluted EPS	73,367	68,132
Basic EPS:
Basic EPS from continuing operations (in dollars per share)	$ 0.58	$ (0.55)
Basic EPS from discontinued operations (in dollars per share)	0.00	0.09
Basic EPS (in dollars per share)	0.58	(0.46)
Diluted EPS:
Diluted EPS from continuing operations (in dollars per share)	0.57	(0.55)
Diluted EPS from discontinued operations (in dollars per share)	0.00	0.09
Diluted EPS (in dollars per share)	$ 0.57	$ (0.46)