Marketable Securities

3 Months Ended

Mar. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

4. Marketable Securities

As of March 31, 2016 and December 31, 2015 the fair value of available-for-sale marketable securities by type of security was as follows:

	March 31, 2016
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
US government obligations	$	3,005	$	1	$	—		$	3,006
Corporate bonds		39,465		9		(18	)		39,456
	$	42,470	$	10	$	(18	)	$	42,462
	December 31, 2015
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Corporate Bonds	$	55,757	$	4	$	(101	)	$	55,660
	$	55,757	$	4	$	(101	)	$	55,660

At March 31, 2016 and December 31, 2015, marketable securities consisted of $39,456,000 and $48,303,000, respectively, of investments that mature within twelve months and $3,006,000 and $7,357,000, respectively, of investments that mature within fifteen months.