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Stock-Based Compensation - Schedule of Fair Value of Employee and Director Stock Options Estimated Using Weighted Average Assumptions (Details)
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]        
Expected term (in years) 6 years 1 month 6 days 6 years 1 month 6 days 6 years 1 month 6 days 6 years 1 month 6 days
Expected volatility 46.90% 60.00% 52.10% 60.00%
Risk-free interest rate 1.94% 1.28% 2.07% 1.45%
Dividend yield 0.00% 0.00% 0.00% 0.00%