Note 2. Cash and Cash Equivalents and Marketable Securities

The Company considers all highly liquid investments, with an original maturity of three months or less at the time of purchase, to be cash equivalents. Investments in debt securities are accounted for as "available-for-sale" securities, carried at fair value with unrealized gains and losses reported in other comprehensive loss, held for use in current operations and classified in current assets as "Marketable investments."

The following tables summarize unrealized gains and losses related to our marketable investments, designated as available-for-sale (in thousands):

March 31, 2013	Amortized Cost		Gross Unrealized Gains			Gross Unrealized Losses			Fair Market Value
Cash and cash equivalents:
Cash	$	1,740		$	—	$	—		$	1,740
Money market funds		12,333			—		—			12,333
Commercial paper		3,199			—		—			3,199
Total cash and cash equivalents		17,272			—		—			17,272

Marketable securities:
U.S. government notes		4,001			5		—			4,006
U.S. government agencies		32,249			44		(1	)		32,292
Municipal securities		5,467			17		(2	)		5,482
Commercial paper		10,958			7		(1	)		10,964
Corporate debt securities		18,011			70		(4	)		18,077
Total marketable investments		70,686			143		(8	)		70,821

Total cash, cash equivalents and marketable investments	$	87,958		$	143	$	(8	)	$	88,093

December 31, 2012	Amortized Cost		Gross Unrealized Gains			Gross Unrealized Losses			Fair Market Value
Cash and cash equivalents:
Cash	$	2,198		$	—	$	—		$	2,198
Money market funds		17,438			—		—			17,348
Commercial paper		4,000			—		—			4,000
Total cash and cash equivalents		23,546			—		—			23,546

Marketable securities:
U.S. government notes		4,005			4		—			4,009
U.S. government agencies		24,910			48		—			24,958
Municipal securities		4,184			23		(1	)		4,206
Commercial paper		10,515			4		—			10,519
Corporate debt securities		18,281			59		(6	)		18,334
Total marketable investments		61,895			138		(7	)		62,026

Total cash, cash equivalents and marketable investments	$	85,441		$	138	$	(7	)	$	85,572

As of March 31, 2013 and December 31, 2012, the total gross unrealized losses were $7,000 and were related to short-term marketable investments. No securities were in unrealized loss positions for more than 12 months.

The following table summarizes the estimated fair value of our securities available-for-sale and classified as cash and cash equivalents and marketable investments classified by the contractual maturity date of the security as of March 31, 2013 (in thousands):

	Amount
Due in less than one year	$	39,455
Due in 1 to 3 years		34,565
Due in 3 to 10 years		—
Due in greater than 10 years		—
	$	74,020