Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

v3.19.3.a.u2
Summary of Significant Accounting Policies - Additional Information (Details)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Weighted Average Fair Value of Stock Grants Using Black-Scholes Valuation Model [Abstract]      
Risk-free interest rate 1.90% 2.60% 1.60%
Expected volatility 73.60% 50.20% 47.30%
Expected life (in years) 3 years 3 months 18 days 3 years 3 months 18 days 3 years 4 months 24 days