Other Intangible Assets and Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets and Liabilities [Line Items]
Amortized intangible assets, gross carrying amount	$ 661		$ 661
Amortized intangible assets, accumulated amortization	240		231
Amortized intangible liabilities, gross carrying amount	1,403		1,403
Amortized intangible liabilities, accumulated amortization	860		$ 836
Amortization of Intangible Assets	9	$ 10
Amortization of Intangible Liabilities	24	$ 25
Finite-Lived Intangible Assets and Liabilities, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of intangible assets, Remainder of 2017	27
Amortization of intangible liabilities, Remainder of 2017	72
Amortization of intangible assets, 2018	33
Amortization of intangible liabilities, 2018	90
Amortization of intangible assets, 2019	31
Amortization of intangible liabilities, 2019	27
Amortization of intangible assets, 2020	31
Amortization of intangible liabilities, 2020	26
Amortization of intangible assets, 2021	31
Amortization of intangible liabilities, 2021	$ 24