Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2013

Accounting Policies [Abstract]

Concentration Risk, Credit Risk, Policy [Policy Text Block]

Concentrations. Three licensees individually accounted for 34%, 31% and 19% of revenues recognized during the three months ended September 30, 2013, and two licensees accounted for 43% and 17% of revenues recognized during the nine months ended September 30, 2013. Five licensees individually accounted for 30%, 13%, 10%, 10% and 10% of revenues recognized during the three months ended September 30, 2012 and four licensees accounted for 29%, 20%, 11% and 10% of revenues recognized during the nine months ended September 30, 2012. Four licensees individually represented approximately 32%, 27%, 18% and 16% of accounts receivable at September 30, 2013. Three licensees individually represented approximately 34%, 30%, and 25% of accounts receivable at December 31, 2012. For the three and nine months ended September 30, 2013, 54% and 26%, respectively, of revenues were attributable to licensees domiciled in foreign jurisdictions. For the three and nine months ended September 30, 2012, 12% and 45%, respectively, of revenues were attributable to licensees domiciled in foreign jurisdictions.

Marketable Securities

Short-term marketable securities for the periods presented were comprised of the following (in thousands):

	September 30, 2013
Security Type	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government fixed income securities(1)	$	167,788	$	60	$	(850	)	$	166,998
Total short-term investments	$	167,788	$	60	$	(850	)	$	166,998

⁽¹⁾ Maturity dates ranging from 2013 to 2014.

	December 31, 2012
Security Type	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
U.S. government fixed income securities	$	87,394	$	20	$	(411	)	$	87,003
Equity securities of certain technology companies	3,254		—		(782		)	2,472
Total short-term investments	$	90,648	$	20	$	(1,193	)	$	89,475