Changes in Carrying Amount of Goodwill (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010
Goodwill [Line Items]
Beginning Balance	$ 1,595,764	$ 1,394,091
Goodwill acquired during year	353,600	213,082
Goodwill allocation adjustments	(11,114)	(10,079)
Sale of assets	(2,887)	(2,345)
Changes due to currency fluctuation	(21,660)	1,015
Ending Balance	1,913,703	1,595,764
United States
Goodwill [Line Items]
Beginning Balance	1,279,758	1,153,149
Goodwill acquired during year	232,850	125,272
Goodwill allocation adjustments	(6,192)	3,682
Sale of assets	0	(2,345)
Changes due to currency fluctuation	0	0
Ending Balance	1,506,416	1,279,758
International countries
Goodwill [Line Items]
Beginning Balance	316,006	240,942
Goodwill acquired during year	120,750	87,810
Goodwill allocation adjustments	(4,922)	(13,761)
Sale of assets	(2,887)	0
Changes due to currency fluctuation	(21,660)	1,015
Ending Balance	$ 407,287	$ 316,006

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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+ Details

- Definition

The aggregate amount of goodwill acquired in the period and allocated to the reportable segment. The value is stated at fair value based on the purchase price allocation.

+ References+ Details

- Definition

The increase (decrease) in the recorded value of goodwill for foreign currency translation adjustments and purchase accounting adjustments needed to revise the carrying amount of goodwill to fair value.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-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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+ Details

- Definition

Write-off of the carrying amount of goodwill associated with all or a portion of a reporting unit that is sold in the period.

+ References+ Details