Annual report pursuant to Section 13 and 15(d)

Long-Term Debt (Debt) (Details)

v3.20.4
Long-Term Debt (Debt) (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Aug. 20, 2020
Feb. 04, 2020
Dec. 31, 2019
Dec. 06, 2019
Debt Instrument [Line Items]          
Finance Lease, Liability, Noncurrent $ 150     $ 163  
Less debt issuance costs, net (50)     (40)  
Debt, Current (410)     (18)  
Long-term Debt, Term 4,549     5,101  
Less current portion (410)     (18)  
Long-term portion of debt and finance lease obligations 4,549     5,101  
Long-term Debt 4,959     5,119  
Line of credit facility maximum borrowing capacity $ 2,950        
Debt instrument interest rate stated percentage 3.50%        
5.125% Senior Secured Notes due 2022          
Debt Instrument [Line Items]          
Debt instrument interest rate stated percentage 3.125%        
4.375% Senior Secured Notes due 2023, net of original issue discount          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 0     500  
Debt instrument interest rate stated percentage 5.125% 5.125%      
4.85% Senior Secured Notes due 2024, net of original issue discount          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 750     750  
Debt instrument interest rate stated percentage 4.375%        
4.45% Senior Secured Notes due 2025, net of original issue discount          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 600     600  
Debt instrument interest rate stated percentage 4.85%        
4.75% Senior Secured Notes due 2027          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 599     599  
Debt instrument interest rate stated percentage 4.45%        
5.45% Senior Secured Notes due 2034, net of original issue discount          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 399     399  
Debt instrument interest rate stated percentage 5.45%        
5.95% Senior Secured Notes due 2043, net of original issue discount          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 300     300  
Debt instrument interest rate stated percentage 5.95%        
6.375% Senior Secured Notes [Member]          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 225     225  
Debt instrument interest rate stated percentage 6.375%        
6.25% Senior Secured Notes [Member] [Member]          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 500     500  
Debt instrument interest rate stated percentage 6.25%       6.25%
Senior secured credit facility          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 0     1,105  
Finance lease obligations (note 9)          
Debt Instrument [Line Items]          
Finance Lease, Liability, Noncurrent 168     181  
4.75% Senior Secured Notes [Member] [Member]          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 575     0  
Debt instrument interest rate stated percentage 4.75%   4.75%    
4.375% Senior Secured Notes due 2028          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 500     0  
Debt instrument interest rate stated percentage 4.375% 4.375%      
Exchangeable Senior Debentures Due 2031 [Member]          
Debt Instrument [Line Items]          
Debt Instrument Net Of Unamortized Discounts Premium $ 393     $ 0  
Debt instrument interest rate stated percentage 3.50%