Contingencies - Additional Information (Detail)							1 Months Ended				9 Months Ended
	Apr. 26, 2015	Jan. 13, 2014 USD ($)	Dec. 23, 2013 USD ($)	Dec. 21, 2013 USD ($)	Jan. 24, 2013 USD ($)	Aug. 11, 2011 USD ($)	Aug. 31, 2011 USD ($)	Apr. 30, 2011 USD ($) LegalMatter	Jan. 31, 2010 USD ($)	Apr. 30, 1999 USD ($)	Sep. 30, 2015 USD ($)	Nov. 11, 2014 USD ($)	Jul. 26, 2013 USD ($)	Apr. 27, 2009 USD ($)	Jul. 17, 2008 USD ($)
MGA
Commitments and Contingencies Disclosure [Line Items]
Historical jury verdict														$ 100,000,000	$ 100,000,000
Claimed trade secrets | LegalMatter								26
Other claimed trade secrets | LegalMatter								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					$ 138,000,000
Payment of Judgment			$ 138,000,000
Approximate amount of judgment finalized in the District Court, including interest				$ 138,000,000
Reasonably possible range of loss, minimum											$ 0
Reasonably possible range of loss, maximum											12,500,000
Reasonably possible range of pre-judgment interest, minimum											0
Reasonably possible range of pre-judgment interest, maximum											10,000,000
Accrued litigation liability											0
MGA | Minimum
Commitments and Contingencies Disclosure [Line Items]
Alleged trade secrets damages claimed		$ 1,000,000,000
Yellowstone
Commitments and Contingencies Disclosure [Line Items]
Reasonably possible range of loss, minimum											0
Reasonably possible range of loss, maximum											11,200,000
Alleged loss of profits										$ 1,000,000
Unpaid accounts receivable											4,000,000
Alleged business investments											3,000,000
Initial court appointed expert estimated loss of profits											1,000,000
Court awarded damages from counterclaim									$ 4,000,000
Damages including attorney fees awarded by Appeals Court including inflation and interest												$ 14,500,000	$ 17,000,000
Counterclaim Awarded By Appeals Court											$ 5,000,000	$ 7,500,000	$ 7,500,000
Percentage of fine imposed on value of the claims made	1.00%