Marketable Securities

6 Months Ended

Jun. 30, 2016

Marketable Securities [Abstract]

Marketable Securities

Note 4.      marketable securities

The amortized cost and fair value of marketable securities were as follows (in thousands):

As of June 30, 2016		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Corporate bonds	$	144,591	$	131	$	(45)	$	144,677
Asset backed securities		28,263		70		-		28,333
Certificates of deposit		20,800		-		-		20,800
Commercial paper		18,224		-		-		18,224
U.S. government bonds		12,601		21		-		12,622
Agency bonds		2,400		1		-		2,401
Municipal bonds		1,400		5		-		1,405
International government bonds		601		-		-		601
Total marketable securities	$	228,880	$	228	$	(45)	$	229,063
As of December 31, 2015		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Corporate bonds	$	177,810	$	24	$	(221)	$	177,613
U.S. government bonds		12,881		-		(10)		12,871
Agency bonds		12,068		-		(3)		12,065
Certificates of deposit		3,500		-		-		3,500
Commercial paper		3,491		-		-		3,491
International government bonds		1,462		-		(3)		1,459
Municipal bonds		1,400		-		(1)		1,399
Treasury bill		1,192		1		-		1,193
Total marketable securities	$	213,804	$	25	$	(238)	$	213,591

As of June 30, 2016, unrealized losses on marketable securities that have been in a continuous loss position for more than twelve months were not material. Our portfolio of marketable securities had an average AA- credit rating as of June 30, 2016. There were no marketable securities that we consider to be other-than-temporarily impaired as of June 30, 2016.

Remaining contractual maturities of marketable securities were as follows (in thousands):

As of June 30, 2016		Amortized Cost		Fair Value
Due in one year or less	$	192,177	$	192,284
Due after one year through three years		36,703		36,779
	$	228,880	$	229,063