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Acquisitions and Investments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Acquisition	Dec. 31, 2011 Acquisition	Dec. 31, 2010 Acquisition
Acquired Finite-Lived Intangible Assets [Line Items]
Aggregate purchase price of acquisitions	$ 500
Intangible assets		273
Weighted average life	5 years
All Other Acquisitions [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisitions completed	17	9	12
Aggregate purchase price of acquisitions	2,880	1,038	556
Intangible assets	981	273	299
Weighted average life	18 years	16 years	18 years
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	473	119	116
Weighted average life	20 years	14 years	15 years
Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	159	39	59
Weighted average life	16 years	35 years	30 years
Other intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	348	115	124
Weighted average life	17 years	12 years	15 years
Goodwill [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 1,000

X

- Definition

Business Acquisition Purchase Price Allocation Intangible Assets

+ References

No definition available.

+ Details

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- Details

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X

- Definition

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16265-109275

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X

- Definition

The total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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X

- Definition

The number of businesses acquired by the entity during the period.

+ References

No definition available.

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