Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Weighted Average Assumptions) (Details)

v3.20.4
Stock-Based Compensation (Weighted Average Assumptions) (Details) - $ / shares
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Summary of weighted average assumptions used to value options granted      
Grant date fair value of options (in dollars per share) $ 0 $ 21.55 $ 0
Volatility 0.00% 40.00% 0.00%
Risk-free interest rate 0.00% 2.50% 0.00%
Dividend yield 0.00% 0.00% 0.00%
Expected term (in years) 0 years 6 years 6 months 0 years