Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financial Statement Presentation
Maximum ownership percentage	20.00%
Royalty Revenue
Number of days licensees have after the end of the quarter to provide notification of royalty revenue	60 days
Number of days licensees have after the end of the quarter to provide payment of royalty revenue	60 days
Number of days licensees have after the end of the quarter to provide payment of fixed royalty revenue	45 days
Number of types of royalty revenue streams	2
Stock-Based Compensation and Equity Incentive Plans
Discount from the fair market value (as a percent)	15.00%
Cash and Cash Equivalents
Maximum original maturity of cash equivalents (in months)	3 months
Minimum
Intangible Assets
Useful life (in years)	1 year	1 year
Maximum
Intangible Assets
Useful life (in years)	10 years	10 years