Allocation of Aggregate Purchase Price of Acquisitions (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended		1 Months Ended		12 Months Ended
	Dec. 31, 2012		Dec. 31, 2012 Minimum	Dec. 31, 2012 Maximum	Dec. 31, 2011 Series of Individually Immaterial Business Acquisitions	Dec. 31, 2011 Series of Individually Immaterial Business Acquisitions Minimum	Dec. 31, 2011 Series of Individually Immaterial Business Acquisitions Maximum	Dec. 31, 2012 Kiva Systems, Inc	Dec. 31, 2012 Kiva Systems, Inc Minimum	Dec. 31, 2012 Kiva Systems, Inc Maximum
Schedule of Business Acquisitions, Purchase Price Allocation [Line Items]
Acquired intangible assets estimated useful lives			1 year	10 years		2 years	10 years		4 years	10 years
Acquired intangible assets, weighted-average amortization period (in years)	5 years 1 month 6 days	[1]			8 years			5 years
Purchase price allocation, contingent liability related to historic tax exposures					$ 38

[1] Intangible assets have estimated useful lives of between one and 10 years.