Other Intangible Assets and Liabilities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Finite-Lived Intangible Assets and Liabilities [Line Items]
Amortized intangible assets, gross carrying amount	$ 659		$ 2,031
Amortized intangible assets, accumulated amortization	182		1,519
Amortized intangible liabilities, gross carrying amount	1,403		2,056
Amortized intangible liabilities, accumulated amortization	709		$ 1,274
Amortization of Intangible Assets	48	$ 233
Amortization of Intangible Liabilities	88	$ 134
Finite-Lived Intangible Assets and Liabilities, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Amortization of intangible assets, Remainder of 2015	10
Amortization of intangible liabilities, Remainder of 2015	27
Amortization of intangible assets, 2016	39
Amortization of intangible liabilities, 2016	101
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