Income Taxes - Components of Net Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Postretirement benefits	$ 299	$ 327
Intangible assets	(1,470)	(1,435)
Investments in non-US subsidiaries	(188)	(263)
Other, net	194	219
Net deferred tax assets	$ (1,165)	$ (1,152)