Financial Instruments - Assets and Liabilities Measured on Recurring Basis - Footnotes (Detail) - USD ($) $ in Millions	9 Months Ended
Oct. 01, 2017	Dec. 31, 2016
Footnotes to selected financial assets and liabilities:
Gross unrealized gain	$ 406
Gross unrealized loss	$ 119
Fair Value, Measurements, Recurring [Member]
Footnotes to selected financial assets and liabilities:
Percentage of financial assets and liabilities measured at fair value inputs Level 1 and Level 3 inputs (less than)	5.00%
Trading equity funds	$ 274	$ 236
Trading debt funds	74	89
Trading securities held in trust	63	71
Not Designated as Hedging Instrument [Member] \| Foreign Currency Forward-Exchange Contracts [Member] \| Fair Value, Measurements, Recurring [Member]
Footnotes to selected financial assets and liabilities:
Instruments used as offsets (assets)	40	162
Instruments used as offsets (liabilities)	60	113
Not Designated as Hedging Instrument [Member] \| Foreign Currency Swap [Member] \| Fair Value, Measurements, Recurring [Member]
Footnotes to selected financial assets and liabilities:
Instruments used as offsets (liabilities)		269
Level 2 [Member] \| Estimate of Fair Value Measurement [Member]
Footnotes to selected financial assets and liabilities:
Fair value of long-term debt	39,000	$ 34,900
Foreign Currency Long Term Debt [Member] \| Level 2 [Member] \| Estimate of Fair Value Measurement [Member]
Footnotes to selected financial assets and liabilities:
Fair value of long-term debt	$ 4,700

Financial Assets And Liabilities Measured At Fair Value, Percentage

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Footnotes to selected financial assets and liabilities [Abstract]

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Amount of unrealized gain before deducting unrealized loss on investments in equity securities classified as available-for-sale securities.

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Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale equity securities.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Total of all securities that are purchased with the intent to be sold in the short-term and that are pledged to one or more secured parties who have the right to buy, sell, or re-pledge the collateral.

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