Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2015

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, 2015
(In thousands)	Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Weighted Rate of Return
Money market funds	$	175,972	$	175,972	$	—	$	—		0.01	%
Corporate notes, bonds and commercial paper	146,649		146,735		2		(88		)	0.40	%
Total cash equivalents and marketable securities	322,621		322,707		2		(88		)
Cash	25,505		25,505		—		—
Total cash, cash equivalents and marketable securities	$	348,126	$	348,212	$	2	$	(88	)



	As of December 31, 2014
(In thousands)	Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Weighted Rate of Return
Money market funds	$	124,938	$	124,938	$	—	$	—		0.01	%
Corporate notes, bonds and commercial paper	145,983		146,096		1		(114		)	0.25	%
Total cash equivalents and marketable securities	270,921		271,034		1		(114		)
Cash	29,188		29,188		—		—
Total cash, cash equivalents and marketable securities	$	300,109	$	300,222	$	1	$	(114	)

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, 2015		December 31, 2014
	(In thousands)
Cash equivalents	$	175,972	$	124,938
Short term marketable securities	146,649		145,983
Total cash equivalents and marketable securities	322,621		270,921
Cash	25,505		29,188
Total cash, cash equivalents and marketable securities	$	348,126	$	300,109

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, 2015 and December 31, 2014 are as follows:



	Fair Value				Gross Unrealized Loss
	June 30, 2015		December 31, 2014		June 30, 2015			December 31, 2014
	(In thousands)
Less than one year
Corporate notes, bonds and commercial paper	$	126,434	$	139,989	$	(88	)	$	(114	)