Useful Lives of Acquired Intangible Assets (Detail)	12 Months Ended
	Dec. 31, 2012
Order Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets useful life	6 months
Product Development [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets useful life	4 years
Minimum [Member] | Customer Relationship [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets useful life	10 years
Minimum [Member] | Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets useful life	8 years
Maximum [Member] | Customer Relationship [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets useful life	15 years
Maximum [Member] | Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets useful life	9 years