Available For Sale Marketable Debt Securities (Tables)

12 Months Ended

Dec. 31, 2011

Dec. 31, 2010

Available For Sale Marketable Debt Securities [Abstract]

Summary Of Amortized Cost And Estimated Fair Value Of Marketable Debt Securities Available For Sale

								Estimated
			Unrealized					Fair
	Cost		Gain		(Loss)			Value
Corporate bonds	$	25,680	$	53	$	(24	)	$	25,709

								Estimated
			Unrealized					Fair
	Cost		Gain		(Loss)			Value
Corporate bonds	$	27,654	$	213	$	(1	)	$	27,866

Summary Of Contractual Maturities Of Available For Sale Debt Securities

	December 31, 2011
			Estimated Fair
	Cost		Value
Less than one year	$	15,271	$	15,260
Due between 1-2 years		8,344		8,357
Due between 2-5 years		2,065		2,092
Total	$	25,680	$	25,709