Available For Sale Marketable Debt Securities (Tables)

6 Months Ended

Jun. 30, 2012

Available-for-sale Securities [Abstract]

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

			Unrealized				Estimated Fair
	Cost		Gain		(Loss)		Value
Corporate bonds	$	19,400	$	59	$	—	$	19,459

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

Summary Of Contractual Maturities Of Available For Sale Debt Securities

	June 30, 2012
	Cost		Estimated Fair Value
Less than one year	$	15,786	$	15,814
Due between 1-2 years	2,700		2,730
Due between 2-5 years	914		915
Total	$	19,400	$	19,459