v3.19.3.a.u2
Long-Term Debt and Revolving Credit Arrangements - Narrative (Details) - USD ($)
1 Months Ended 12 Months Ended
May 14, 2019
Sep. 30, 2019
Oct. 31, 2018
Apr. 30, 2018
Jul. 31, 2016
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2015
Jun. 13, 2018
Debt Instrument [Line Items]                    
Total debt           $ 5,791,000,000 $ 7,491,000,000      
Embedded derivative liability (income) expense $ (117,000,000)         $ (58,000,000) 501,000,000 $ 173,000,000    
Secured Loans | 2016 Senior Secured Term Loan                    
Debt Instrument [Line Items]                    
Proceeds from issuance of secured debt         $ 1,200,000,000          
Debt discount         23,000,000          
Debt issuance costs         $ 13,000,000          
Effective Interest Rate           6.10%       6.10%
Total debt           $ 1,113,000,000 1,124,000,000      
Secured Loans | 2018 Senior Secured Term Loan                    
Debt Instrument [Line Items]                    
Proceeds from issuance of secured debt       $ 1,500,000,000            
Debt discount       8,000,000            
Debt issuance costs       $ 15,000,000            
Effective Interest Rate           6.20%        
Total debt           $ 1,478,000,000 1,493,000,000      
Convertible Notes | 2021 Convertible Notes                    
Debt Instrument [Line Items]                    
Debt discount                 $ 1,100,000,000  
Debt issuance costs                 $ 1,000,000  
Effective Interest Rate           23.50%     23.50%  
Total debt           $ 0 1,844,000,000      
Proceeds from issuance of convertible debt                 $ 1,700,000,000  
Stated interest rate                 2.50%  
Duration for interest type payment election                 4 years  
Interest rate increase during final 2 year initial term                 12.50%  
Embedded derivative liability (income) expense           $ (20,000,000) 434,000,000 89,000,000    
Convertible Notes | 2021 Convertible Notes | Minimum                    
Debt Instrument [Line Items]                    
Interest rate during maturity extension period                 3.50%  
Discount on conversion price rate                 18.00%  
Convertible Notes | 2021 Convertible Notes | Maximum                    
Debt Instrument [Line Items]                    
Interest rate during maturity extension period                 12.50%  
Discount on conversion price rate                 30.50%  
Convertible Notes | 2022 Convertible Notes                    
Debt Instrument [Line Items]                    
Proceeds from issuance of secured debt                 $ 949,000,000  
Debt discount                 312,000,000  
Debt issuance costs                 $ 100,000  
Effective Interest Rate           13.70%        
Total debt           $ 0 1,030,000,000      
Extension period                 1 year  
Stated interest rate                 2.50%  
Convertible Notes, internal rate of return                 8.00%  
Redemption period                 3 years  
Embedded derivative liability (income) expense           $ (38,000,000) 67,000,000 $ 84,000,000    
Convertible Notes | 2022 Convertible Notes | Minimum                    
Debt Instrument [Line Items]                    
Discount on conversion price rate                 8.10%  
Convertible Notes | 2022 Convertible Notes | Maximum                    
Debt Instrument [Line Items]                    
Discount on conversion price rate                 44.50%  
Senior Note                    
Debt Instrument [Line Items]                    
Aggregate principal amount     $ 2,000,000,000.0              
Senior Note | 2023 Senior Note                    
Debt Instrument [Line Items]                    
Debt issuance costs     $ 9,000,000              
Effective Interest Rate           7.70%        
Total debt           $ 500,000,000 500,000,000      
Stated interest rate     7.50%              
Debt instrument term     5 years              
Aggregate principal amount     $ 500,000,000              
Senior Note | 2023 Senior Note | Level 2                    
Debt Instrument [Line Items]                    
Debt instrument, fair value disclosure           $ 523,000,000        
Senior Note | 2026 Senior Note                    
Debt Instrument [Line Items]                    
Effective Interest Rate           8.10%        
Total debt           $ 1,500,000,000 1,500,000,000      
Stated interest rate     8.00%              
Debt instrument term     8 years              
Aggregate principal amount     $ 1,500,000,000              
Senior Note | 2026 Senior Note | Level 2                    
Debt Instrument [Line Items]                    
Debt instrument, fair value disclosure           $ 1,600,000,000        
Senior Note | 2027 Senior Note                    
Debt Instrument [Line Items]                    
Debt issuance costs   $ 11,000,000                
Effective Interest Rate           7.70%        
Total debt           $ 1,200,000,000 0      
Stated interest rate   7.50%                
Debt instrument term   8 years                
Aggregate principal amount   $ 1,200,000,000                
Senior Note | 2027 Senior Note | Level 2                    
Debt Instrument [Line Items]                    
Debt instrument, fair value disclosure           1,200,000,000        
Line of Credit | Revolving Credit Facility                    
Debt Instrument [Line Items]                    
Borrowing capacity           2,300,000,000        
Line of credit balance           0        
Line of Credit | Letters of Credit                    
Debt Instrument [Line Items]                    
Letters of credit outstanding           570,000,000 470,000,000      
Letters of credit outstanding that will reduce the available credit under facilities           $ 213,000,000 $ 166,000,000