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Stock-Based Compensation Plan - Schedule of Fair Value Assumptions Stock Options (Details) - Employee Stock Option - USD ($)
9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected life of options granted, in years 4 years 5 months 3 days 4 years 3 months 28 days
Risk-free interest rate (as a percent) 1.49% 1.26%
Expected volatility of stock (as a percent) 29.64% 29.67%
Annual expected dividend yield (as a percent) 3.00% 3.00%
Fair value of granted options $ 806,422 $ 433,479
Non-vested options $ 316,946 $ 303,539