Annual report pursuant to Section 13 and 15(d)

STOCK-BASED COMPENSATION (Fair value assumptions) (Details)

v3.20.4
STOCK-BASED COMPENSATION (Fair value assumptions) (Details)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Payment Arrangement [Abstract]      
Risk-free interest rate, minimum 0.09% 1.89% 2.68%
Risk-free interest rate, maximum 1.19% 2.53% 2.70%
Dividend yield 0.00% 0.00% 0.00%
Volatility factors, minimum 32.37% 27.63% 27.66%
Volatility factors, maximum 51.83% 28.12% 28.00%
Weighted average expected life (in years) 2 years 6 months 3 days 6 years 29 days 5 years 8 months 26 days