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Stockholders' Equity - Summary of Assumptions Used to Value Stock-Based Awards Granted (Details)
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract]    
Expected term (in years) 5 years 6 years 1 month 6 days
Risk-free interest rate, Minimum 2.51% 2.32%
Risk-free interest rate, Maximum 2.56% 2.67%
Expected volatility 36.00%  
Expected volatility, Minimum   39.00%
Expected volatility, Maximum   40.00%