Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended	1 Months Ended
	Sep. 30, 2012	Aug. 31, 2011 Mga	Apr. 30, 2011 Mga LegalMatter	Apr. 27, 2009 Mga	Jul. 17, 2008 Mga
Commitments and Contingencies Disclosure [Line Items]
Historical jury verdict				$ 100	$ 100
Claimed trade secrets			26
Other claimed trade secrets			88
Compensatory damages awarded by jury			88.5
Reduced compensatory damages awarded by court		85.0
Punitive damages awarded		85.0
Attorney fees and costs awarded	140	140
Compensatory damages, punitive damages, and attorney fees and costs awarded by court		310
Compensatory damages and punitive damages awarded by court	$ 170