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Stock Based Compensation - Summary of Activity for Outstanding and Exercisable SARs (Detail) - Stock Appreciation Rights (SARs) [Member] - USD ($)
3 Months Ended
Mar. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
SARs outstanding 469,565 599,334
SARs exercisable 398,868  
Weighted Average Base Value, SARs outstanding $ 28.74  
Weighted Average Base Value, SARs exercisable $ 28.32  
Weighted Average Remaining Contractual Life, SARs outstanding 3 years 10 months 24 days  
Weighted Average Remaining Contractual Life, SARs exercisable 3 years 8 months 12 days  
Aggregate Intrinsic Value, SARs outstanding $ 18,787  
Aggregate Intrinsic Value, SARs exercisable $ 16,127