Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2015

Fair Value Measurements

Schedule of financial instruments measured at fair value on recurring basis

	Actively Quoted		Significant
	Markets for		Other		Significant
	Identical		Observable		Unobservable		Balance at
	Assets		Inputs		Inputs		March 31,
	Level 1		Level 2		Level 3		2015
	(In thousands)
As of March 31, 2015:
Assets
Money market deposits	$	10,625	$	—	$	—	$	10,625
Commercial paper		—		19,748		—		19,748
Corporate debt securities		—		48,292		—		48,292
Corporate equity securities		—		37,002		—		37,002
Total	$	10,625	$	105,042	$	—	$	115,667

	Actively Quoted		Significant
	Markets for		Other		Significant
	Identical		Observable		Unobservable		Balance at
	Assets		Inputs		Inputs		December 31,
	Level 1		Level 2		Level 3		2014
	(In thousands)
As of December 31, 2014:
Assets
Money market deposits	$	12,397	$	—	$	—	$	12,397
Commercial paper		—		29,749		—		29,749
Corporate debt securities		—		46,435		—		46,435
Total	$	12,397	$	76,184	$	—	$	88,581

Summary of available-for-sale marketable securities

	March 31, 2015
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gains		Losses		Fair Value
	(In thousands)
Commercial paper	$	19,734	$	14	$	—	$	19,748
Corporate debt securities		48,310		—		(18)		48,292
Corporate equity securities		13,857		23,145		—		37,002
Total	$	81,901	$	23,159	$	(18)	$	105,042

	December 31, 2014
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gains		Losses		Fair Value
	(In thousands)
Commercial paper	$	29,730	$	19	$	—	$	29,749
Corporate debt securities		44,219		—		(34)		44,185
Total	$	73,949	$	19	$	(34)	$	73,934