v3.6.0.2
Stock-Based Compensation Plans (Information Regarding Stock Options) (Details) - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Options granted during period 0 0 0
Shares      
Outstanding — beginning of year 84,261 97,962 97,962
Exercised (84,261) (13,701) 0
Canceled 0 0 0
Outstanding — end of year 0 84,261 97,962
Exercisable — end of year 0 84,261 97,962
Weighted Average Exercise Price      
Outstanding — beginning of year $ 17.42 $ 16.61 $ 16.61
Exercised 17.42 11.66 0.00
Canceled 0.00 0.00 0.00
Outstanding — end of year 0.00 17.42 16.61
Exercisable — end of year $ 0.00 $ 17.42 $ 16.61
Weighted Average Remaining Contractual Life   1 year 1 year 9 months 18 days
Total intrinsic value of stock options exercised $ 2,400,000 $ 1,000,000 $ 1,000,000
Stock Options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
General expiration period, from date of grant or time of termination (years) 10 years    
Options granted during period 0 0 0
Weighted Average Exercise Price      
Number of stock options vested $ 0 $ 0 $ 0
Stock Options | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
General vesting period (years) 1 year    
Stock Options | Minimum | Share-based Compensation Award, Tranche One      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
General vesting period (years) 1 year    
Stock Options | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
General vesting period (years) 5 years    
Stock Options | Maximum | Share-based Compensation Award, Tranche Two      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
General vesting period (years) 3 years