Marketable Securities

Available-for-sale marketable securities and cash and cash equivalents consist of the following (in thousands):



	December 31, 2016
	Amortized Cost Value		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash and cash equivalents:
Cash	$	77,443	$	—	$	—		$	77,443
Money market	173,631		—		—			173,631
Domestic corporate commercial paper	5,487		—		—			5,487
Domestic corporate debt securities	2,006		—		—			2,006
Total	$	258,567	$	—	$	—		$	258,567
Marketable securities:
Domestic corporate debt securities	$	19,317	$	—	$	(2	)	$	19,315
Domestic corporate commercial paper	31,852		78		—			31,930
Asset-backed securities	22,639		—		(4		)	22,635
Total	$	73,808	$	78	$	(6	)	$	73,880



	December 31, 2015
	Amortized Cost Value		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash and cash equivalents:
Cash	$	2,934	$	—	$	—		$	2,934
Money market funds	83,257		—		—			83,257
Domestic corporate commercial paper	39,984		—		—			39,984
Government-sponsored enterprise debt securities	15,996		$	—	$	—		15,996
Domestic corporate debt securities	10,007		$	—	$	—		10,007
Asset-backed securities	7,500		$	—	$	—		7,500
Total	$	159,678	$	—	$	—		$	159,678
Marketable securities:
Domestic corporate debt securities	$	173,142	—		$	(107	)	$	173,035
Domestic corporate commercial paper	84,004		154		—			84,158
Asset-backed securities	56,510		$	1	$	(43	)	56,468
Total	$	313,656	$	155	$	(150	)	$	313,661

There were no debt securities that had been in an unrealized loss position for more than 12 months as of December 31, 2016 or December 31, 2015. There were 13 debt securities in an unrealized loss position for less than 12 months at December 31, 2016 and there were 57 debt securities that had been in an unrealized loss position for less than 12 months at December 31, 2015. The aggregate unrealized loss on these securities as of December 31, 2016 and 2015 was approximately $6 thousand and $150 thousand, respectively, and the fair value was $35.7 million and $225.7 million, respectively. The Company considered the decline in market value for these securities to be primarily attributable to current economic conditions. As it was not more likely than not that the Company would be required to sell these securities before the recovery of their amortized cost basis, which may be maturity, the Company did not consider these investments to be other-than-temporarily impaired as of December 31, 2016 and 2015.

As of December 31, 2016 and 2015, marketable securities solely consisted of investments that mature within one year.