Summary of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earning per share reconciliation
Net income	$ 2,418	$ 6,325	$ 15,070	$ 15,364
Weighted-average common shares outstanding	76,278	76,534	76,323	76,521
Earnings per share, basic	$ 0.03	$ 0.08	$ 0.20	$ 0.20
Net income	$ 2,418	$ 6,325	$ 15,070	$ 15,364
Weighted-average common shares outstanding	76,278	76,534	76,323	76,521
Effect of assumed exercise of stock options and RSUs	2,804	2,640	2,653	2,385
Weighted-average common shares outstanding, assuming dilution	79,082	79,174	78,976	78,906
Earnings per share, diluted	$ 0.03	$ 0.08	$ 0.19	$ 0.19
Outstanding options, warrants and RSUs excluded as impact would be antidilutive	296	320	368	201
Stock Options
Earning per share reconciliation
Weighted-average effect of dilutive securities	1,613	1,603	1,556	1,546
RSUs
Earning per share reconciliation
Weighted-average effect of dilutive securities	1,191	1,037	1,097	839

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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