v3.20.1
Debt (First Lien Term Loans) (Details) - USD ($)
$ in Millions
Mar. 31, 2020
Dec. 31, 2019
Debt Instrument [Line Items]    
Long-term debt $ 10,259 $ 11,857
2024 First Lien Term Loan    
Debt Instrument [Line Items]    
Long-term debt 1,511 1,514
2026 First Lien Term Loans    
Debt Instrument [Line Items]    
Long-term debt 1,650 1,653
First Lien Term Loans    
Debt Instrument [Line Items]    
Long-term debt $ 3,161 $ 3,167