Restructuring Charges/Other - Components of Restructuring Charges and Other (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring And Related Activities [Abstract]
Restructuring charges	[1]									$ 14	$ 20	$ 126
Gains on sales of assets										(83)	(75)	0
Gain on technology transfer										0	0	(315)
Other										(2)	4	0
Restructuring charges/other		$ (68)	$ 0	$ (1)	$ (2)	$ (27)	$ (9)	$ (4)	$ (11)	$ (71)	$ (51)	$ (189)

[1] Includes severance and benefits, along with changes in estimates; 2014 and 2013 also include other exit costs and accelerated depreciation.