Stockholders' Equity - Summary of the Company's Stock Options Activity (Detail) - Stock Options $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, Options outstanding, beginning of year (in shares) | shares	1,008
Number of options, Granted (in shares) | shares	0
Number of options, Exercised (in shares) | shares	(171)
Number of options, Expired / terminated (in shares) | shares	(6)
Number of options, Options outstanding, end of year (in shares) | shares	831
Number of options, Options exercisable, end of period (in shares) | shares	802
Number of options, Options expected to vest, end of period (in shares) | shares	25
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price, Options outstanding, beginning of year (in dollars per share) | $ / shares	$ 5.40
Weighted average exercise price, Granted (in dollars per share) | $ / shares	0.00
Weighted average exercise price, Exercised (in dollars per share) | $ / shares	7.35
Weighted average exercise price, Expired / terminated (in dollars per share) | $ / shares	10.43
Weighted average exercise price, Options outstanding, end of period (in dollars per share) | $ / shares	4.98
Weighted average exercise price, Options exercisable, end of period (in dollars per share) | $ / shares	4.99
Weighted average exercise price, Options expected to vest, end of period (in dollars per share) | $ / shares	$ 4.75
Weighted average remaining contractual life, Options outstanding, end of period	1 year 7 months 28 days
Weighted average remaining contractual life, Options exercisable, end of period	1 year 8 months 5 days
Weighted average remaining contractual life, Options expected to vest, end of period	1 year 2 months 23 days
Aggregate intrinsic value, Options outstanding, end of period | $	$ 14,706
Aggregate intrinsic value, Options exercisable, end of period | $	14,180
Aggregate intrinsic value, Options expected to vest, end of period | $	$ 448