Aggregate Purchase Price of the Acquisitions (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Schedule of Business Acquisitions, Cost of Acquired Entity [Line Items]
Cash paid, net of cash acquired	$ 637
Existing equity interest	89
Indemnification holdbacks	25
Stock options assumed	20
Purchase price of acquired entities	771		228	26
Goodwill	615		111	16
Intangible assets	230	[1]	91	5
Fixed assets	119
Deferred tax assets	49
Other assets acquired	68
Accounts payable	(65)
Debt	(70)
Deferred tax liabilities	(75)
Other liabilities assumed	(100)	[2]
Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net, Total	771
Marketing-related
Schedule of Business Acquisitions, Cost of Acquired Entity [Line Items]
Intangible assets	130
Contract-based
Schedule of Business Acquisitions, Cost of Acquired Entity [Line Items]
Intangible assets	6
Customer-related
Schedule of Business Acquisitions, Cost of Acquired Entity [Line Items]
Intangible assets	$ 94

[1] Amortization periods range from 2 to 10 years, with a weighted-average amortization period of 8 years.

[2] Includes a $38 million contingent liability related to historic tax exposures.