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Stock-Based Compensation Plans - Summary of Transactions of the Company's Stock Option Plans (Detail) - Stock Options Plan [Member]
3 Months Ended
Mar. 31, 2016
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Outstanding, Number of Options, Beginning balance | shares 667,439
Exercised, Number of Options | shares (47,212)
Forfeited, Number of Options | shares (10,832)
Outstanding, Number of Options, Ending balance | shares 687,889
Outstanding, Weighted Average Exercise Price, Beginning balance $ 19.87
Exercised, Weighted Average Exercise Price 5.26
Forfeited, Weighted Average Exercise Price 13.82
Outstanding, Weighted Average Exercise Price, Ending balance 20.23
Outstanding, Weighted Average Grant-Date Fair Value 20.19
Exercised 28.63
Forfeited, Weighted Average Grant-Date Fair Value 1.00
Outstanding, Weighted Average Grant-Date Fair Value $ 20.37
Discount [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Granted, Number of Options | shares 54,642
Granted, Weighted Average Exercise Price $ 0.00
Granted, Weighted Average Grant-Date Fair Value $ 35.91
Market Value [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Granted, Number of Options | shares 23,852
Granted, Weighted Average Exercise Price $ 44.18
Granted, Weighted Average Grant-Date Fair Value $ 9.11