Marketable Securities (Tables)

3 Months Ended

Mar. 31, 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 March 31, 2016
(In thousands)	Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Weighted Rate of Return
Money market funds	$	90,342	$	90,342	$	—	$	—		0.20	%
U.S. Government bonds and notes	14,057		14,061		—		(4		)	0.48	%
Corporate notes, bonds, commercial paper and other	74,886		74,910		2		(26		)	0.56	%
Total cash equivalents and marketable securities	179,285		179,313		2		(30		)
Cash	46,287		46,287		—		—
Total cash, cash equivalents and marketable securities	$	225,572	$	225,600	$	2	$	(30	)

	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
	March 31, 2016		December 31, 2015
	(In thousands)
Cash equivalents	$	90,342	$	108,795
Short term marketable securities	88,943		143,942
Total cash equivalents and marketable securities	179,285		252,737
Cash	46,287		34,969
Total cash, cash equivalents and marketable securities	$	225,572	$	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 March 31, 2016 and December 31, 2015 are as follows:

	Fair Value				Gross Unrealized Loss
	March 31, 2016		December 31, 2015		March 31, 2016			December 31, 2015
	(In thousands)
Less than one year
U.S. Government bonds and notes	$	10,212	$	14,110	$	(4	)	$	(32	)
Corporate notes, bonds and commercial paper	47,247		145,563		(26		)	(156		)
Total Corporate notes, bonds, and commercial paper and U.S. Government bonds and notes	$	57,459	$	159,673	$	(30	)	$	(188	)