Quarterly report pursuant to Section 13 or 15(d)

Intangible Assets (Amortization Expense of Amortizable Intangible Assets) (Details)

v3.8.0.1
Intangible Assets (Amortization Expense of Amortizable Intangible Assets) (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Finite-Lived Intangible Assets [Line Items]    
Amortization expense $ 5 $ 5
Franchise agreements    
Finite-Lived Intangible Assets [Line Items]    
Amortization expense 4 4
Management agreements    
Finite-Lived Intangible Assets [Line Items]    
Amortization expense $ 1 $ 1