v3.20.4
Fair Value Measurements - Fair Value of Short-term Investments and Long-term Debt (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Vendor Financing Arrangement    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Term loans $ 240 $ 25
Level 1 | Carrying Amount | Senior Notes    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt 29,966 10,958
Level 1 | Carrying Amount | Senior Notes | Third Party    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt 36,204 0
Level 1 | Fair Value | Senior Notes    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt 32,450 11,479
Level 1 | Fair Value | Senior Notes | Third Party    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt 40,519 0
Level 2 | Carrying Amount | Secured Term Loan    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Term loans 0 4,000
Level 2 | Carrying Amount | Senior Notes | Affiliates    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt 4,716 9,986
Level 2 | Fair Value | Secured Term Loan    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Term loans 0 4,000
Level 2 | Fair Value | Senior Notes | Affiliates    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Long-term debt $ 4,991 $ 10,366