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Incentive Stock Plans - Schedule of Assumptions used for Performance Shares (Details) - Performance Shares
1 Months Ended 12 Months Ended
Jul. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected volatility   21.90%   23.20%
Risk-free rate   0.90%   0.40%
Re-issued 2014 Performance Shares        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected volatility     19.70%  
Risk-free rate     0.70%  
Maximum term (in years) 2 years 6 months      
2014 Performance Shares, as originally issued        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected volatility 22.80%      
Risk-free rate 0.80%