Marketable Securities

12 Months Ended

Dec. 31, 2017

3. Marketable Securities

The Company’s marketable securities held as of December 31, 2017 and 2016 are summarized below:


	December 31, 2017
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
(in thousands)
Money Market Funds	$	5,175	$	—	$	—	$	5,175
Corporate Securities		123,860		—		(590)		123,270
Government Securities		224,739		—		(1,209)		223,530
	$	353,774	$	—	$	(1,799)	$	351,975

Reported as
Cash and cash equivalents							$	5,175
Marketable securities								346,800
Total investments							$	351,975


	December 31, 2016
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
(in thousands)
Money Market Funds	$	12,137	$	—	$	—	$	12,137
Corporate Securities		182,394		6		(917)		181,483
Government Securities		207,986		44		(565)		207,465
	$	402,517	$	50	$	(1,482)	$	401,085

Reported as
Cash and cash equivalents							$	12,137
Marketable securities								388,948
Total investments							$	401,085

The maturities of the Company’s marketable securities as of December 31, 2017 are as follows:


	Amortized		Estimated
	Cost		Fair Value
(in thousands)
Mature in one year or less	$	208,200	$	207,603
Mature after one year through five years		140,399		139,197
	$	348,599	$	346,800

The unrealized losses on available-for-sale investments and their related fair values as of December 31, 2017 and 2016 are as follows:


	December 31, 2017
	Less than 12 months				12 months or greater
		Fair value		Unrealized losses		Fair value		Unrealized losses
(in thousands)
Corporate Securities	$	79,290	$	(137)	$	43,980	$	(453)
Government Securities		128,313		(461)		95,217		(748)
	$	207,603	$	(598)	$	139,197	$	(1,201)


	December 31, 2016
	Less than 12 months				12 months or greater
		Fair value		Unrealized losses		Fair value		Unrealized losses
(in thousands)
Corporate Securities	$	82,215	$	(133)	$	88,990	$	(784)
Government Securities		17,573		(16)		149,694		(549)
	$	99,788	$	(149)	$	238,684	$	(1,333)

The unrealized losses from the listed securities are due to a change in the interest rate environment and not a change in the credit quality of the securities.