Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2015

Marketable Securities [Abstract]

Amortized Cost And Fair Value Of Marketable Securities

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

Contractual Maturities Of Marketable Securities

As of December 31, 2015		Amortized Cost		Fair Value
Due in one year or less	$	147,735	$	147,626
Due after one through two years		66,069		65,965
	$	213,804	$	213,591