Weighted Average Useful Life of Each Component of Computer Software (Detail) (Computer Software, Intangible Asset)	12 Months Ended
	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Yrs)	5 years 9 months 18 days
Licensed computer software
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Yrs)	5 years 6 months
Software development costs
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Yrs)	5 years 10 months 24 days
Acquisition technology intangibles
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Yrs)	6 years 7 months 6 days