Short-Term Marketable Securities

12 Months Ended

Dec. 31, 2013

Investments Debt And Equity Securities [Abstract]

Short-Term Marketable Securities

2. Short-Term Marketable Securities

The following is a summary of short-term marketable securities classified as available-for-sale (in thousands):

December 31, 2013	Amortized Cost		Unrealized Gain		Unrealized Loss		Market Value
U.S. treasuries	$	1,500	$	3	$	—	$	1 ,503
Government-sponsored enterprise securities		4,500		—		—		4,500
Corporate bonds		4,853		—		—		4,853
Certificates of deposit		685		—		—		685
	$	11,538	$	3	$	—	$	11,541
December 31, 2012	Amortized Cost		Unrealized Gain		Unrealized Loss		Market Value
U.S. treasuries	$	10,135	$	1	$	—	$	10,136
Government-sponsored enterprise securities		15,507		—		1		15,506
Corporate bonds		11,509		—		8		11,501
Certificates of deposit		496		—		—		496
	$	37,647	$	1	$	9	$	37,639

At December 31, 2013, $4.2 million of these securities were scheduled to mature outside of one year. There were no net realized gains (losses) on sales of available-for-sale securities for the years ended December 31, 2013, 2012 and 2011. None of these investments have been in a continuous unrealized loss position for more than 12 months as of December 31, 2013 and 2012.