Cash Equivalents and Investments (Tables)

9 Months Ended

Sep. 30, 2012

Cash Equivalents and Investments [Abstract]

The amortized cost and fair value of cash and cash equivalents

The amortized cost and fair value of cash and cash equivalents at September 30, 2012 were as follows (unaudited, in thousands):

	Amortized		Gross Unrealized					Fair
	Cost		Gains		Losses			Value
Money market funds	$	18,086	$	2	$	—		$	18,088
Government-sponsored agencies		6,006		2		(1	)		6,007
Commercial paper		32,132		—		—			32,132
Corporate debt securities		71,247		52		(4	)		71,295
Total available-for-sale securities	$	127,471	$	56	$	(5	)	$	127,522
Classified as:
Cash equivalents								$	12,392
Short-term investments									112,357
Long-term investments									2,773
Total available-for-sale securities								$	127,522

The amortized cost and fair value of cash and cash equivalents at December 31, 2011 were as follows (in thousands):

	Amortized		Gross Unrealized					Fair
	Cost		Gains		Losses			Value
Money market funds	$	41,266	$	—	$	—		$	41,266
Government-sponsored agencies		9,042		2		—			9,044
Commercial paper		12,540		1		—			12,541
Corporate debt securities		32,528		9		(43	)		32,494
Total available-for-sale securities	$	95,376	$	12	$	(43	)	$	95,345
Classified as:
Cash equivalents								$	39,414
Short-term investments									49,335
Long-term investments									6,596
Total available-for-sale securities								$	95,345