Acquired Intangible Assets (Parenthetical) (Detail)	1 Months Ended
	Dec. 31, 2012
Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life, maximum (in years)	1 year
Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life, maximum (in years)	10 years