v3.20.4
Fair Value of Financial Assets and Liabilities - Narrative (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Long-term debt $ 7,609 $ 7,365
Level 2 | Estimate of Fair Value Measurement [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Long-term debt $ 8,600 $ 7,900