Fair Value of Financial Instruments

6 Months Ended

Jun. 30, 2011

Fair Value of Financial Instruments [Abstract]

Fair Value of Financial Instruments

Note 3. Fair Value of Financial Instruments

Cash and investment holdings, accounts receivable, accounts payable and accrued liabilities are presented in the financial statements at their carrying amounts, which are reasonable estimates of fair value due to their short maturities.

The fair value of financial assets and liabilities is measured under a framework that establishes “levels” which are defined as follows: Level 1 fair value is determined from observable, quoted prices in active markets for identical assets or liabilities. Level 2 fair value is determined from quoted prices for similar items in active markets or quoted prices for identical or similar items in markets that are not active. Level 3 fair value is determined using the entity’s own assumptions about the inputs that market participants would use in pricing an asset or liability.

The fair value of our investment holdings at June 30, 2011 and December 31, 2010 is summarized in the following tables (in thousands).

	June 30, 2011
	Total Fair		Fair Value Determined Under:
	Value		(Level 1)		(Level 2)		(Level 3)
Commercial paper	$	600	$	—	$	600	$	—
U.S. government agency securities		4,009		—		4,009		—
Money market funds		25,288		25,288		—		—
Total	$	29,897	$	25,288	$	4,609	$	—

			December 31, 2010
	Total Fair		Fair Value Determined Under:
	Value		(Level 1)		(Level 2)		(Level 3)
Commercial paper	$	18,415	$	—	$	18,415	$	—
U.S. government agency securities		30,628		—		30,628		—
Total	$	49,043	$	—	$	49,043	$	—

Commercial paper and U.S. government agency securities are classified as part of either cash and cash equivalents or short-term investments in the condensed consolidated balance sheets. The carrying value of short-term investments consisted of the following as of June 30, 2011 and December 31, 2010 (in thousands).

	June 30, 2011
	Amortized		Unrealized		Unrealized		Fair Market
	Cost		Gains		Losses		Value
Commercial paper	$	600	$	—	$	—	$	600
U.S. government agency securities		4,009		—		—		4,009
Total	$	4,609	$	—	$	—	$	4,609

	December 31, 2010
	Amortized		Unrealized		Unrealized			Fair Market
	Cost		Gains		Losses			Value
Commercial paper	$	18,415	$	—	$	—		$	18,415
U.S. government agency securities		30,629		2		(3	)		30,628
Total	$	49,044	$	2	$	(3	)	$	49,043

Available-for-sale marketable securities with maturities of three months or less from date of purchase have been classified as cash equivalents, and amounted to $2.2 million and $15.2 million as of June 30, 2011 and December 31, 2010, respectively.