Summary 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
Earning per share reconciliation
Net income	$ 27,021	$ 10,400
Weighted-average common shares outstanding	76,761	76,375
Earnings per share, basic	$ 0.35	$ 0.14
Net income	$ 27,021	$ 10,400
Weighted-average common shares outstanding	76,761	76,375
Effect of assumed exercise of stock options and RSUs	5,114	2,860
Weighted-average common shares outstanding, assuming dilution	81,875	79,235
Earnings per share, diluted	$ 0.33	$ 0.13
Outstanding options and RSUs excluded as impact would be antidilutive	314	492
Stock Options
Earning per share reconciliation
Weighted-average effect of dilutive securities	3,184	1,692
RSUs
Earning per share reconciliation
Weighted-average effect of dilutive securities	1,930	1,168

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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