Difference Between Effective Tax Rate (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Reconciliation Of Statutory Federal Tax Rate [Line Items]
Federal income tax at U.S. federal statutory rate	$ 306	$ 273	$ 922	$ 728
Foreign income tax rate differential	(29)	(42)	(109)	(108)
State income tax, net of federal benefit	7	6	24	17
Nondeductible expenses		9	23	33
Tax impact of foreign exchange	(12)	(14)	(30)	(26)
Tax benefit of manufacturing deduction	2	33	22	43
Foreign dividends, net of foreign tax credits	(15)	13	(33)	14
Tax rate change on temporary differences		(5)		(18)
Other	6	(21)		(16)
Provision for income taxes	$ 265	$ 252	$ 819	$ 667

Tax rate change on temporary differences.

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Tax impact of foreign exchange.

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The sum of domestic current and deferred income tax expense or benefit attributable to continuing operations.

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The sum of foreign current income tax expense or benefit and foreign deferred income tax expense or benefit pertaining to Income or Loss from continuing foreign operations.

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The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to the deduction for dividends paid or received under enacted tax laws.

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The sum of the differences between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to nondeductible expenses under enacted tax laws, or differences in the methodologies used to determine expense amounts for financial statements prepared in accordance with generally accepted accounting principles and enacted tax laws.

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The component of income tax expense representing amounts paid or payable (or refundable) which are classified as "income taxes" as determined by applying the provisions of enacted tax law to other than the taxable Income or Loss from continuing operations for the period. Items affecting income taxes and required to be disclosed, but not included elsewhere, would also be designated as "Other".

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The sum of state and local current and deferred income tax expense or benefit attributable to continuing operations.

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