(3) Cash, Cash Equivalents and Marketable Securities

A summary of cash, cash equivalents and available-for-sale marketable securities held by the Company as of March 31, 2015 and December 31, 2014 was as follows in thousands (see Note 2):

	March 31, 2015
	Cost		Unrealized gains		Unrealized losses			Fair value

Cash and cash equivalents:
Cash and money market funds (Level 1)	$	21,720	$	—	$	—		$	21,720
Corporate debt securities due within 3 months of date of purchase (Level 2)	11,535		—		—			11,535
Total cash and cash equivalents	$	33,255	$	—	$	—		$	33,255
Marketable securities:
Corporate debt securities due within 1 year of date of purchase (Level 2)	43,345		11		(5		)	43,351
Total cash, cash equivalents and marketable securities	$	76,600	$	11	$	(5	)	$	76,606

	December 31, 2014
	Cost		Unrealized gains		Unrealized losses			Fair value

Cash and cash equivalents:
Cash and money market funds (Level 1)	$	45,004	$	—	$	—		$	45,004
Corporate debt securities due within 3 months of date of purchase (Level 2)	1,020		—		—			1,020
Total cash and cash equivalents	$	46,024	$	—	$	—		$	46,024
Marketable securities:
Corporate debt securities due within 1 year of date of purchase (Level 2)	51,662		12		(8		)	51,666
Total cash, cash equivalents and marketable securities	$	97,686	$	12	$	(8	)	$	97,690