Tax - Difference Between Effective Tax Rate (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Federal income tax at U.S. federal statutory rate	$ (118)	$ 137	$ (201)	$ 313
Foreign income tax rate differential	3	(41)	(24)	(87)
State income tax, net of federal benefit	(1)		(5)	3
Nondeductible expenses	9	12	21	17
Tax benefit of manufacturing deduction				(10)
Foreign dividends, net of foreign tax credits	(24)	8	(19)	15
Tax impact of foreign exchange	1	(19)	(7)	(18)
Change in valuation allowance	11	3	21	6
Tax rate change on temporary differences	(5)	1	(3)	(3)
Change in tax reserves	3		(20)	69
Other		4	(2)	(11)
Provision for income taxes	$ (121)	$ 105	$ (239)	$ 294

Income tax reconciliation deductions dividends adjustments.

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