Acquisitions and Investments - Estimated Fair Values of Assets Acquired and Liabilities (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
Goodwill	$ 167us-gaap_GoodwillAcquiredDuringPeriod	$ 1,903us-gaap_GoodwillAcquiredDuringPeriod	$ 1,000us-gaap_GoodwillAcquiredDuringPeriod
Total assets acquired	406	3,329	3,672
Total liabilities	115	932	792
All Other Acquisitions [Member]
Business Acquisition [Line Items]
Current assets, net of cash acquired		428	1,441
Property, plant and equipment		250	248
Intangible assets		894	981
Goodwill		1,590	1,000
Other assets		49	2
Total assets acquired		3,211	3,672
Current liabilities		186	585
Long-term debt			1
Other liabilities		123	206
Total liabilities		833	792
Cash consideration, net of cash acquired		$ 2,378	$ 2,880

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Amount of assets acquired at the acquisition date.

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Amount of assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of liabilities assumed at the acquisition date.

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Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of other assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.

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The amount of property, plant, and equipment recognized as of the acquisition date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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