Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net income from continuing operations	$ 39,302	$ 59,459	$ 1,975	$ 135,911
Net income from discontinued operations, net of tax	5,409	0	11,625	0
Net income	$ 44,711	$ 59,459	$ 13,600	$ 135,911
Weighted-average shares used to calculate basic EPS	69,729	56,935	68,931	56,798
Effect of dilutive securities:
Employee equity awards	635	564	644	612
Weighted-average shares used to calculate diluted EPS	70,364	57,499	69,575	57,410
Basic EPS from continuing operations (in dollars per share)	$ 0.56	$ 1.04	$ 0.03	$ 2.39
Basic EPS from discontinued operations (in dollars per share)	0.08	0.00	0.17	0.00
Basic EPS (in dollars per share)	0.64	1.04	0.20	2.39
Diluted EPS from continuing operations (in dollars per share)	0.56	1.03	0.03	2.37
Diluted EPS from discontinued operations (in dollars per share)	0.08	0.00	0.17	0.00
Diluted EPS (in dollars per share)	$ 0.64	$ 1.03	$ 0.20	$ 2.37