Marketable Securities (Tables)

3 Months Ended

Mar. 31, 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 March 31, 2015
(In thousands)	Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Weighted Rate of Return
Money market funds	$	151,054	$	151,054	$	—	$	—		0.01	%
Corporate notes, bonds and commercial paper	146,194		146,254		8		(68		)	0.34	%
Total cash equivalents and marketable securities	297,248		297,308		8		(68		)
Cash	20,513		20,513		—		—
Total cash, cash equivalents and marketable securities	$	317,761	$	317,821	$	8	$	(68	)



	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
	March 31, 2015		December 31, 2014
	(In thousands)
Cash equivalents	$	151,054	$	124,938
Short term marketable securities	146,194		145,983
Total cash equivalents and marketable securities	297,248		270,921
Cash	20,513		29,188
Total cash, cash equivalents and marketable securities	$	317,761	$	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 March 31, 2015 and December 31, 2014 are as follows:



	Fair Value				Gross Unrealized Loss
	March 31, 2015		December 31, 2014		March 31, 2015			December 31, 2014
	(In thousands)
Less than one year
Corporate notes, bonds and commercial paper	$	110,382	$	139,989	$	(68	)	$	(114	)