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Stock-Based Compensation - Weighted Average Assumptions for PRSUs (Details) - PRSUs
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total expected term (in years) 2 years 10 months 9 days 2 years 10 months 9 days 2 years 11 months 1 day
Expected volatility 43.50% 39.00% 42.10%
Risk-free interest rate 2.48% 2.35% 1.51%
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Correlation range 2.40% 11.00% 26.80%
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Correlation range 88.10% 85.70% 76.00%