Other Intangible Assets and Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Amortized intangible assets, gross carrying amount	$ 661		$ 661		$ 661
Amortized intangible assets, accumulated amortization	258		258		231
Amortized intangible liabilities, gross carrying amount	1,403		1,403		1,403
Amortized intangible liabilities, accumulated amortization	908		908		$ 836
Amortization of Intangible Assets	9	$ 10	27	$ 29
Amortization of Intangible Liabilities	24	$ 25	72	$ 75
Finite-Lived Intangible Assets and Liabilities, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of intangible assets, Remainder of 2017	9		9
Amortization of intangible liabilities, Remainder of 2017	24		24
Amortization of intangible assets, 2018	33		33
Amortization of intangible liabilities, 2018	90		90
Amortization of intangible assets, 2019	31		31
Amortization of intangible liabilities, 2019	27		27
Amortization of intangible assets, 2020	31		31
Amortization of intangible liabilities, 2020	26		26
Amortization of intangible assets, 2021	31		31
Amortization of intangible liabilities, 2021	$ 24		$ 24