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Stock-Based Compensation - Assumptions Used to Estimate Fair Value (Details) - Stock Options
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Dividend yield 1.20% 1.20% 1.40%
Expected volatility 33.00% 32.00% 32.00%
Risk free interest rate 0.50% 2.40% 2.90%
Weighted average expected option life in years 6 years 2 months 12 days 6 years 3 months 18 days 5 years 10 months 24 days