Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Supplemental Guarantor Information Supplemental Guarantor Information - Condensed Consolidating Cash Flows - Balances per Condensed Consolidating Balance Sheet (Details) - USD ($)
$ in Millions
Jun. 30, 2018
Dec. 31, 2017
Jun. 30, 2017
Dec. 31, 2016
Balances per Consolidated Balance Sheet:        
Cash and cash equivalents $ 0 $ 0    
Restricted cash 1,521 1,589    
Total cash, cash equivalents and restricted cash 1,521 1,589 $ 1,563 $ 605
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
Parent Issuer [Member]        
Balances per Consolidated Balance Sheet:        
Cash and cash equivalents 0 0    
Restricted cash 663 1,033    
Total cash, cash equivalents and restricted cash 663 1,033 278 234
Guarantors [Member]        
Balances per Consolidated Balance Sheet:        
Cash and cash equivalents 0 0    
Restricted cash 12 12    
Total cash, cash equivalents and restricted cash 12 12 8 13
Non-Guarantor [Member]        
Balances per Consolidated Balance Sheet:        
Cash and cash equivalents 0 0    
Restricted cash 846 544    
Total cash, cash equivalents and restricted cash $ 846 $ 544 $ 1,277 $ 358