Income Taxes (Schedule Of Deferred Taxes) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Abstract]
NOL carry-forwards	$ 137,870	$ 124,695
Research and development credit	8,085	8,085
Deferred revenue	3,808	7,227
Investments		4,266
Stock-based compensation	2,831	3,108
Other	2,375	2,262
Deferred tax assets	154,969	149,643
Investments	(4,953)
Other	(389)	(420)
Net deferred tax asset before valuation allowance	149,627	149,223
Valuation allowance	(149,627)	(149,223)
Net deferred tax assets