Stock-based Compensation - Summary of Stock Option Activity (Detail)	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Shares, Beginning Balance | shares	156,636
Number of Shares, Granted | shares	0
Number of Shares, Exercised | shares	(11,417)
Number of Shares, Forfeited | shares	0
Number of Shares, Ending Balance | shares	145,219
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning Balance (in $ per share) | $ / shares	$ 18.78
Weighted Average Exercise Price, Granted (in $ per share) | $ / shares	0.00
Weighted Average Exercise Price, Exercised (in $ per share) | $ / shares	34.97
Weighted Average Exercise Price, Forfeited (in $ per share) | $ / shares	0.00
Weighted Average Exercise Price, Ending Balance (in $ per share) | $ / shares	$ 17.51