Basis of Presentation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2014
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Description of royalty revenue	Royalty revenue is recognized when the fees are fixed or determinable, which is known when we receive notice of the amounts earned pursuant to our third party royalty arrangements. Typically, we receive notice of royalty revenues earned on a quarterly basis 30 to 60 days after the end of the reporting period.
Minimum [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Notice of royalty revenue earned quarterly after the end of the reporting period	30 days
Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Notice of royalty revenue earned quarterly after the end of the reporting period	60 days