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Stock-Based Compensation - Assumptions Used in Valuation and Weighted Average Fair Value of Stock Option Grants (Details) - $ / shares
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Share-based Payment Arrangement [Abstract]    
Weighted average fair value of grants (in dollars per share) $ 17.70 $ 10.28
Risk-free interest rate 1.44% 2.49%
Expected volatility 43.95% 41.64%
Expected life 4 years 7 months 2 days 4 years 6 months 15 days