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Income Taxes - Difference Between Effective Tax Rate (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal income tax at U.S. statutory rate	$ (137)	$ (918)	$ (206)
Foreign income tax rate differential	(21)	32	(110)
Goodwill impairment		271	462
Nondeductible expenses	38	30	66
Foreign dividends, net of foreign tax credits	(132)	(25)	28
Tax rate change on timing differences	(245)	(8)	(45)
Change in uncertain tax positions	81	11	69
Prior years taxes	(26)	(29)	(47)
Tax impact on foreign exchange	5	(4)	(46)
Change in deferred tax valuation allowance	280	476	15
Other	1	(43)	(8)
Total income tax provision	$ (156)	$ (207)	$ 178

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