Acquisitions, Goodwill, and Acquired Intangible Assets - Allocation of Aggregate Purchase Price of Acquisitions (Parenthetical) (Detail)	12 Months Ended		1 Months Ended		12 Months Ended
	Dec. 31, 2013		Dec. 31, 2013 Minimum	Dec. 31, 2013 Maximum	Dec. 31, 2012 Kiva Systems, Inc	Dec. 31, 2012 Kiva Systems, Inc Minimum	Dec. 31, 2012 Kiva Systems, Inc 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
Purchase Price
Acquired intangible assets estimated useful lives			1 year	10 years		4 years	10 years		2 years	10 years
Acquired intangible assets, weighted-average amortization period (in years)	4 years 2 months 12 days	[1]			5 years			8 years

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