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Stock-Based Compensation Plans - Summary of Transactions of the Company's Stock Option Plans (Detail) - Stock Options Plan [Member]
12 Months Ended
Dec. 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 (151,164)
Forfeited, Number of Options | shares (37,621)
Outstanding, Number of Options, Ending balance | shares 570,994
Outstanding, Weighted Average Exercise Price, Beginning balance $ 19.87
Exercised, Weighted Average Exercise Price 14.38
Forfeited, Weighted Average Exercise Price 14.49
Outstanding, Weighted Average Exercise Price, Ending balance 20.38
Outstanding, Weighted Average Grant-Date Fair Value 20.19
Exercised 19.63
Forfeited, Weighted Average Grant-Date Fair Value 24.83
Outstanding, Weighted Average Grant-Date Fair Value $ 21.68
Discount [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Granted, Number of Options | shares 67,546
Granted, Weighted Average Exercise Price $ 0.00
Granted, Weighted Average Grant-Date Fair Value $ 38.13
Market Value [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Granted, Number of Options | shares 24,794
Granted, Weighted Average Exercise Price $ 44.34
Granted, Weighted Average Grant-Date Fair Value $ 9.17