Cash and Cash Equivalents and Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2013

Cash and Cash Equivalents and Marketable Securities [Abstract]

Unrealized gains and losses related to marketable investments and long-term investments

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

June 30, 2013	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Cash and cash equivalents:
Cash	$	2,027	$	—	$	—		$	2,027
Money market funds		7,858		—		—			7,858
Commercial paper		2,000		—		—			2,000
Total cash and cash equivalents		11,885		—		—			11,885
Marketable securities:
U.S. government notes		4,005		1		—			4,006
U.S. government agencies		34,577		24		(47	)		34,554
Municipal securities		3,120		7		(6	)		3,121
Commercial paper		15,597		7		—			15,604
Corporate debt securities		20,432		41		(17	)		20,456
Total marketable investments		77,731		80		(70	)		77,741
Total cash, cash equivalents and marketable investments	$	89,616	$	80	$	(70	)	$	89,626

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		17,348		—		—			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

Estimated fair value of marketable investments and long-term investments classified by contractual maturity date

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 June 30, 2013 (in thousands):

	Amount
Due in less than one year	$	39,862
Due in 1 to 3 years		39,879
Due in 3 to 10 years		—
Due in greater than 10 years		—
	$	79,741