Other (Income) Expense - Net (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Income and Expenses [Abstract]
(Gain) loss on sale and revaluation of assets			$ (572)	$ (351)	$ (41)
(Gain) Loss on Extinguishment of Debt	$ 189		189	0	0
(Gain) Loss on derivatives		$ 102	0	102	40
Net (gain) loss on marketable securities transactions			0	0	(8)
Other Nonoperating (Income) Expense			62	2	(44)
Other (income) expense - net			$ (321)	$ (247)	$ (53)