Short-Term Investments

6 Months Ended

Jun. 30, 2011

Short-Term Investments

Short-Term Investments

5. Short-Term Investments

The following tables present the financial assets measured at fair value on a recurring basis as of December 31, 2009 and 2010 and June 30, 2011 (in thousands):

	December 31, 2009
			Unrealized
	Amortized Cost		Gross Gains		Gross Losses			Net Gain (Loss)			Fair Value
Assets:
Money market funds (1)	$	5,233	$	—	$	—		$	—		$	5,233
	December 31, 2010
			Unrealized
	Amortized Cost		Gross Gains		Gross Losses			Net Gain (Loss)			Fair Value
Assets:
Money market funds (1)	$	36,560	$	—	$	—		$	—		$	36,560
	June 30, 2011 (unaudited)
			Unrealized
	Amortized Cost		Gross Gains		Gross Losses			Net Gain (Loss)			Fair Value
Assets:
Money market funds (1)	$	156,743	$	—	$	—		$	—		$	156,743
U.S. Government and Agency securities		39,324		2		(22	)		(20	)		39,304
		196,067		2		(22	)		(20	)		196,047

(1) These assets are included within cash and cash equivalents.

The maturity of the Company's entire investment portfolio was less than one year as of June 30, 2011 with the exception of $10.0 million in par value which had a stated maturity of 13 months (unaudited). The maturity of the Company's entire investment portfolio was less than one year as of December 31, 2009 and 2010. As of June 30, 2011, no individual securities have incurred continuous unrealized losses for greater than 12 months (unaudited). The Company did not have any realized gains (losses) on marketable securities during any of the periods presented (unaudited).