Quarterly report pursuant to Section 13 or 15(d)

Supplemental Guarantor Information - Condensed Consolidating Cash Flows - Balances per Condensed Consolidating Balance Sheet (Details)

v3.19.1
Supplemental Guarantor Information - Condensed Consolidating Cash Flows - Balances per Condensed Consolidating Balance Sheet (Details) - USD ($)
$ in Millions
Mar. 31, 2019
Dec. 31, 2018
Mar. 31, 2018
Dec. 31, 2017
Balances per Consolidated Balance Sheet:        
Cash and cash equivalents $ 0 $ 0    
Restricted cash 1,297 1,541    
Total cash, cash equivalents and restricted cash 1,297 1,541 $ 1,477 $ 1,589
Parent Issuer [Member]        
Balances per Consolidated Balance Sheet:        
Cash and cash equivalents 0 0    
Restricted cash 661 779    
Total cash, cash equivalents and restricted cash 661 779 903 1,033
Guarantors [Member]        
Balances per Consolidated Balance Sheet:        
Cash and cash equivalents 0 0    
Restricted cash 15 6    
Total cash, cash equivalents and restricted cash 15 6 13 12
Non-Guarantors [Member]        
Balances per Consolidated Balance Sheet:        
Cash and cash equivalents 0 0    
Restricted cash 621 756    
Total cash, cash equivalents and restricted cash 621 756 561 544
Eliminations [Member]        
Balances per Consolidated Balance Sheet:        
Cash and cash equivalents 0 0    
Restricted cash 0 0    
Total cash, cash equivalents and restricted cash $ 0 $ 0 $ 0 $ 0