Stock-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Shares, Outstanding, Beginning Balance | shares	170,815
Number of Shares, Exercised | shares	(51,936)
Number of Shares, Outstanding, Ending Balance | shares	118,879
Number of Shares, Exercisable, Ending Balance | shares	118,879
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Outstanding, Beginning Balance	$ 14.84
Weighted Average Exercise Price, Exercised	18.71
Weighted Average Exercise Price, Outstanding, Ending Balance	16.23
Weighted Average Exercise Price, Exercisable, Ending Balance	$ 16.23
Aggregate Intrinsic Value, Outstanding | $	$ 1,528
Aggregate Intrinsic Value, Exercisable | $	$ 1,528
Weighted-average remaining contractual life, options exercisable	4 years 7 months 6 days
Minimum [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Roll Forward]
Option Price Per Share, Outstanding, Beginning Balance (in dollars per share)	$ 2.89
Option Price Per Share, Exercised (in dollars per share)	2.89
Option Price Per Share, Outstanding, Ending Balance (in dollars per share)	2.89
Option Price Per Share, Exercisable, Ending Balance (in dollars per share)	2.89
Maximum [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Roll Forward]
Option Price Per Share, Outstanding, Beginning Balance (in dollars per share)	24.65
Option Price Per Share, Exercised (in dollars per share)	24.65
Option Price Per Share, Outstanding, Ending Balance (in dollars per share)	24.65
Option Price Per Share, Exercisable, Ending Balance (in dollars per share)	$ 24.65