Condensed Consolidated Statements Of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Revenues
Royalties	$ 85,231	$ 83,370	$ 288,479	$ 278,833
License and other		400		10,400
Total revenues	85,231	83,770	288,479	289,233
Operating expenses
General and administrative	5,647	3,960	17,737	13,516
Operating income	79,584	79,810	270,742	275,717
Non-operating expense, net
Loss on retirement or conversion of convertible notes				(766)
Interest and other income, net	1,867	130	2,385	463
Interest expense	(6,514)	(9,007)	(23,087)	(27,941)
Total non-operating expense, net	(4,647)	(8,877)	(20,702)	(28,244)
Income before income taxes	74,937	70,933	250,040	247,473
Income tax expense	26,362	25,017	87,779	87,026
Net income	$ 48,575	$ 45,916	$ 162,261	$ 160,447
Net income per share
Basic (in Dollars per share)	$ 0.35	$ 0.33	$ 1.16	$ 1.15
Diluted (in Dollars per share)	$ 0.32	$ 0.28	$ 1.08	$ 0.88
Weighted average shares outstanding
Basic (in Shares)	139,715	139,680	139,693	139,665
Diluted (in Shares)	149,626	167,019	150,678	186,756
Cash dividends declared per common share (in Dollars per share)			$ 0.60	$ 0.60