Stockholders' Equity (Schedule Of Reconciliation Of Unrealized Gains And Losses On Available For Sale Securities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Gain Loss On Investments By Category [Line Items]
Unrealized (Loss) / Gain on Available for Sale Securities Net-of-Tax Amount beginning balance	$ 137	$ 357
Unrealized (loss) gain on marketable securities, net of tax	(124)	(220)	235
Less: reclassification adjustment for net (gains) losses included in net income, net of tax		(60)	34
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	13	137	357
Unrealized (Loss)/ Gain on Available for Sale Securities Before-Tax Amount, beginning balance	220	575
Pre-tax gain (loss) included in loss on marketable securities and other investments		(97)
Unrealized (Loss)/ Gain on Available for Sale Securities Before-Tax Amount, ending balance	32	220	575
Unrealized (Loss)/ Gain on Available for Sale Securities Tax Benefit (Expenses), beginning balance	(83)	(218)
Less: reclassification adjustment for net (gains) losses included in net income, Tax Benefit (Expenses)		37
Unrealized (Loss)/ Gain on Available for Sale Securities Tax Benefit (Expenses), ending balance	(19)	(83)	(218)
Categories of Investments, Marketable Securities, Available-for-sale Securities [Member]
Gain Loss On Investments By Category [Line Items]
Unrealized (loss) gain on marketable securities, net of tax	(124)	(160)	201
Unrealized (loss) gain on marketable securities, Before-Tax Amount	(188)	(258)
Unrealized (loss) gain on marketable securities, Tax Benefit (Expenses)	$ 64	$ 98