Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans (Details)

v3.20.4
Employee Benefit Plans (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]      
Employer cash contributions $ 30 $ 19 $ 20