Other Intangible Assets and Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets and Liabilities [Line Items]
Amortized intangible assets, gross carrying amount	$ 660		$ 660
Amortized intangible assets, accumulated amortization	202		192
Amortized intangible liabilities, gross carrying amount	1,403		1,403
Amortized intangible liabilities, accumulated amortization	761		$ 736
Amortization of Intangible Assets	10	$ 31
Amortization of Intangible Liabilities	25	$ 34
Finite-Lived Intangible Assets and Liabilities, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of intangible assets, Remainder of 2016	29
Amortization of intangible liabilities, Remainder of 2016	76
Amortization of intangible assets, 2017	36
Amortization of intangible liabilities, 2017	96
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