Asset Impairments and Unusual Items - Components of (Income) Expense from Divestitures, Asset Impairments (Other Than Goodwill) and Unusual Items (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Extraordinary and Unusual Items [Abstract]
(Income) expense from divestitures	$ (7)	$ (515)	$ (8)
Asset impairments (other than goodwill)	89	345	472
(Income) expense from divestitures, asset impairments (other than goodwill) and unusual items	$ 82	$ (170)	$ 464

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

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- References

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- Definition

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2443-110228

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- Definition

The aggregate amount of asset impairment charges other than goodwill impairment, gains and losses related to the divestiture of businesses, and unusual items incurred during an accounting period. Generally, these items are either unusual or infrequent, but not both (in which case they would be extraordinary items).

+ References

No definition available.

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