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Stock-based Compensation - Summary of Stock Option Activity (Detail)
3 Months Ended
Mar. 31, 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 (9,783)
Number of Shares, Forfeited | shares 0
Number of Shares, Ending Balance | shares 146,853
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 38.25
Weighted Average Exercise Price, Forfeited (in $ per share) | $ / shares 0.00
Weighted Average Exercise Price, Ending Balance (in $ per share) | $ / shares $ 17.48