Contingencies - Additional Information (Detail) (USD $)			1 Months Ended							6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jan. 24, 2013 MGA	Aug. 31, 2011 MGA	Apr. 30, 2011 MGA LegalMatter	Apr. 27, 2009 MGA	Jul. 17, 2008 MGA	Jan. 31, 2010 Yellowstone	Apr. 30, 1999 Yellowstone	Jun. 30, 2013 Yellowstone
Commitments and Contingencies Disclosure [Line Items]
Historical jury verdict						$ 100,000,000	$ 100,000,000
Claimed trade secrets					26
Other claimed trade secrets					88
Compensatory damages awarded by jury					88,500,000
Reduced compensatory damages awarded by court				85,000,000
Punitive damages awarded				85,000,000
Attorney fees and costs awarded				140,000,000
Compensatory damages, punitive damages, and attorney fees and costs awarded by court				310,000,000
Damages for alleged trade secret misappropriation appealed				170,000,000
Attorney fees and costs appealed				140,000,000
Amount of damages and attorney's fees and costs vacated by the appeals court			172,500,000
Litigation accrual	137,800,000	137,800,000	137,800,000
Alleged loss of profits									500,000
Unpaid accounts receivable										3,500,000
Alleged business investments										2,800,000
Initial court appointed expert estimated loss of profits										1,200,000
Court awarded damages from counterclaim								3,800,000
Reasonably possible range of loss, minimum										0
Reasonably possible range of loss, maximum										20,000,000
Estimated recovery of legal offset including inflation adjustments										$ 7,000,000