Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

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		December 31,
	Level 1		Level 2		Level 3		2016
	(In thousands)
As of December 31, 2016:
Assets
Money market deposits	$	13,198	$	—	$	—	$	13,198
Commercial paper		—		32,421		—		32,421
Corporate debt securities		—		14,869		—		14,869
Corporate equity securities		—		9,295		—		9,295
Total	$	13,198	$	56,585	$	—	$	69,783

	Actively Quoted		Significant
	Markets for		Other		Significant
	Identical		Observable		Unobservable		Balance at
	Assets		Inputs		Inputs		December 31,
	Level 1		Level 2		Level 3		2015
	(In thousands)
As of December 31, 2015:
Assets
Money market deposits	$	13,928	$	—	$	—	$	13,928
Commercial paper		—		29,224		—		29,224
Corporate debt securities		—		22,359		—		22,359
Corporate equity securities		—		18,126		—		18,126
Total	$	13,928	$	69,709	$	—	$	83,637

Summary of available-for-sale marketable securities

	December 31, 2016
	Cost or		Gross		Gross		Total
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gains		Losses		Fair Value
	(In thousands)
Commercial paper	$	32,350	$	71	$	—	$	32,421
Corporate debt securities		14,868		3		(2)		14,869
Corporate equity securities		7,348		1,947		—		9,295
Total	$	54,566	$	2,021	$	(2)	$	56,585

	December 31, 2015
	Cost or		Gross		Gross		Total
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gains		Losses		Fair Value
	(In thousands)
Commercial paper	$	23,684	$	41	$	—	$	23,725
Corporate debt securities		20,569		—		(10)		20,559
Corporate equity securities		13,857		4,269		—		18,126
Total	$	58,110	$	4,310	$	(10)	$	62,410

Schedule of the breakdown of available-for-sale marketable securities with unrealized losses

	In a Loss Position for
	Less Than 12 Months
	Gross
	Unrealized		Estimated
As of December 31, 2016:	Losses		Fair Value
	(In thousands)
Corporate debt securities	$	(2)	$	9,443
Total	$	(2)	$	9,443