4. Cash, cash equivalents and short-term investments

The following tables summarize our cash, cash equivalents and marketable securities at June 30, 2013 and December 31, 2012 (in thousands):

As of June 30, 2013	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash and money market funds	$	28,193	$	—	$	—		$	28,193
Corporate debt securities
Due in one year or less	20,251		1		(16		)	20,236
Due in two years or less	5,927		—		(11		)	5,916
Total	$	54,371	$	1	$	(27	)	$	54,345
Reported as:
Cash and cash equivalents	$	28,193	$	—	$	—		$	28,193
Short-term investments	26,178		1		(27		)	26,152
Total	$	54,371	$	1	$	(27	)	$	54,345

As of December 31, 2012	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash and money market funds	$	14,776	$	—	$	—		$	14,776
Corporate debt securities
Due in one year or less	5,754		2		(1		)	5,755
Due in two years or less	10,867		3		(10		)	10,860
Total	$	31,397	$	5	$	(11	)	$	31,391
Reported as:
Cash and cash equivalents	$	14,776	$	—	$	—		$	14,776
Marketable securities	16,621		5		(11		)	16,615
Total	$	31,397	$	5	$	(11	)	$	31,391

We held 21 debt securities at June 30, 2013 that had been in an unrealized loss position for less than 12 months. We held no investments that have been in a continuous unrealized loss position for 12 months or longer. The fair value on these securities was $20.2 million. We evaluated our securities for other-than-temporary impairments based on quantitative and qualitative factors. We considered the decline in market value for these 21 securities to be primarily attributable to current economic and market conditions. It is not more likely than not that we will be required to sell these securities, and we do not intend to sell these securities before the recovery of their amortized cost bases, which recovery is expected within the next 12 months. Based on our analysis, we do not consider these investments to be other-than-temporarily impaired as of June 30, 2013.

As of June 30, 2013, we held $13.3 million in financial institution debt securities and other corporate debt securities located in Canada, the United Kingdom, the Netherlands, Australia, and Norway. Based on our analysis, we do not consider these investments to be other-than-temporarily impaired as of June 30, 2013.

We had no material realized gains or losses on our short-term investments for the three months and six months ended June 30, 2013 and 2012. There were no other-than-temporary impairments recognized for the three months and six months ended June 30, 2013 and 2012.