Cash Equivalents and Investments

12 Months Ended

Dec. 31, 2011

Cash Equivalents and Investments [Abstract]

Cash Equivalents and Investments

4. Cash Equivalents and Investments

The components of cash equivalents and investments at December 31, 2010 were as follows (in thousands):

			Unrealized					Fair  Market Value
	Cost		Gains		Losses
Cash equivalents:
Money market funds	$	23,826	$	—	$	—		$	23,826
Commercial paper		31,294		—		—			31,294
Government-sponsored agency debt securities		5,199		—		—			5,199
Certificates of deposit		2,294		—		—			2,294
Short-term investments:
Government-sponsored agency debt securities		5,497		—		(1	)		5,496
Total	$	68,110	$	—	$	(1	)	$	68,109

The components of cash equivalents and investments at December 31, 2011 were as follows (in thousands):

			Unrealized					Fair  Market Value
	Cost		Gains		Losses
Cash equivalents:
Money market funds	$	41,292	$	—	$	—		$	41,292
Commercial paper		3,000		—		—			3,000
Certificates of deposit		1,000		—		—			1,000
Short-term investments:
Commercial paper		1,998		2		—			2,000
U.S. Treasury Securities		1,004		—		—			1,004
Government-sponsored agency debt securities		3,536		—		(1	)		3,535
Certificates of deposit		3,349		7		—			3,356
Total	$	55,179	$	9	$	(1	)	$	55,187

Short-term investments have original maturity dates greater than three months but less than one year.