Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2016

Available-for-sale Securities [Abstract]

Cash equivalents and marketable securities classified as available-for-sale

All cash equivalents and marketable securities are classified as available-for-sale. Total cash, cash equivalents and marketable securities are summarized as follows:



	As of June 30, 2016
(In thousands)	Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Weighted Rate of Return
Money market funds	$	128,034	$	128,034	$	—	$	—		0.22	%
U.S. Government bonds and notes	7,002		7,002		1		(1		)	0.44	%
Corporate notes, bonds, commercial paper and other	74,309		74,348		—		(39		)	0.66	%
Total cash equivalents and marketable securities	209,345		209,384		1		(40		)
Cash	49,986		49,986		—		—
Total cash, cash equivalents and marketable securities	$	259,331	$	259,370	$	1	$	(40	)



	As of December 31, 2015
(In thousands)	Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Weighted Rate of Return
Money market funds	$	77,804	$	77,804	$	—	$	—		0.12	%
U.S. Government bonds and notes	14,110		14,142		—		(32		)	0.48	%
Corporate notes, bonds, commercial paper and other	160,823		160,979		—		(156		)	0.45	%
Total cash equivalents and marketable securities	252,737		252,925		—		(188		)
Cash	34,969		34,969		—		—
Total cash, cash equivalents and marketable securities	$	287,706	$	287,894	$	—	$	(188	)

Available-for-sale securities reported at fair value

Available-for-sale securities are reported at fair value on the balance sheets and classified as follows:



	As of
	June 30, 2016		December 31, 2015
	(In thousands)
Cash equivalents	$	138,025	$	108,795
Short term marketable securities	71,320		143,942
Total cash equivalents and marketable securities	209,345		252,737
Cash	49,986		34,969
Total cash, cash equivalents and marketable securities	$	259,331	$	287,706

Estimated fair value of cash equivalents and marketable securities classified by the length of time that the securities have been in a continuous unrealized loss position

The estimated fair value of cash equivalents and marketable securities classified by the length of time that the securities have been in a continuous unrealized loss position at June 30, 2016 and December 31, 2015 are as follows:



	Fair Value				Gross Unrealized Loss
	June 30, 2016		December 31, 2015		June 30, 2016			December 31, 2015
	(In thousands)
Less than one year
U.S. Government bonds and notes	$	4,002	$	14,110	$	(1	)	$	(32	)
Corporate notes, bonds and commercial paper	73,771		145,563		(39		)	(156		)
Total Corporate notes, bonds, and commercial paper and U.S. Government bonds and notes	$	77,773	$	159,673	$	(40	)	$	(188	)