Note 3. Cash, Cash Equivalents and Marketable Securities

The following table summarizes our cash, cash equivalents and marketable securities (in thousands):


	Cash, Cash Equivalents and Marketable Securities
	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value		Accrued Interest		Total Value
March 31, 2012
Cash and cash equivalents	$	73,776	$	3	$	—	$	73,779	$	—	$	73,779
Commercial Paper		4,798		1		—		4,798		—		4,798
Corporate securities		17,013		92		—		17,106		213		17,319

	$	95,587	$	96	$	—	$	95,683	$	213	$	95,896

Reported as:
Cash and cash equivalents	$	73,776	$	3	$	—	$	73,779	$	—	$	73,779
Marketable securities		21,811		93		—		21,904		213		22,117

	$	95,587	$	96	$	—	$	95,683	$	213	$	95,896

Maturities:
Matures in one year or less	$	95,587	$	96	$	—	$	95,683	$	213	$	95,896
Matures one to three years		—		—		—		—		—		—

	$	95,587	$	96	$	—	$	95,683	$	213	$	95,896

December 31, 2011
Cash and cash equivalents	$	73,144	$	—	$	—	$	73,144	$	—	$	73,144
Corporate securities		24,583		128		—		24,711		276		24,987

	$	97,727	$	128	$	—	$	97,855	$	276	$	98,131

Reported as:
Cash and cash equivalents	$	73,144	$	—	$	—	$	73,144	$	—	$	73,144
Marketable securities		24,583		128		—		24,711		276		24,987

	$	97,727	$	128	$	—	$	97,855	$	276	$	98,131

Maturities:
Matures in one year or less	$	97,727	$	128	$	—	$	97,855	$	276	$	98,131
Matures one to three years		—		—		—		—		—		—

	$	97,727	$	128	$	—	$	97,855	$	276	$	98,131

We did not realize any gains or losses on our investments in marketable securities during the first quarter of 2012 or 2011. To date we have not recorded any impairment charges on marketable securities related to other-than-temporary declines in market value.

The following table presents our assets measured at fair value on a recurring basis (in thousands):


	Level 1		Level 2		Level 3		Total
March 31, 2012
Cash and money market fund	$	38,438	$	—	$	—	$	38,438
Commercial paper		—		40,139		—		40,139
Corporate securities		—		17,319		—		17,319

	$	38,438	$	57,458	$	—	$	95,896


December 31, 2011
Cash and money market fund	$	62,446	$	—	$	—	$	62,446
Commercial paper		—		10,698		—		10,698
Corporate securities		—		24,987		—		24,987

	$	62,446	$	35,685	$	—	$	98,131