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Stock-Based Compensation Plans - Assumptions Used to Determine Grant-Date Fair Value of Options (Detail) - Black-Scholes Model [Member]
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Dividend yield 1.38% 1.03% 1.34%
Expected life 5 years 5 years 5 years
Volatility 25.11% 25.50% 30.70%
Risk free interest rate 0.91% 1.05% 0.97%