Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2017

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		June 30,
	Level 1		Level 2		Level 3		2017
	(In thousands)
As of June 30, 2017:
Assets
Money market deposits	$	10,830	$	—	$	—	$	10,830
Commercial paper		—		37,774		—		37,774
Corporate debt securities		—		29,825		—		29,825
Total	$	10,830	$	67,599	$	—	$	78,429

	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

Summary of available-for-sale marketable securities

	June 30, 2017
	Cost or		Gross		Gross		Total
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gains		Losses		Fair Value
	(In thousands)
Commercial paper	$	37,782	$	1	$	(8)	$	37,775
Corporate debt securities		29,842		—		(18)		29,824
Total	$	67,624	$	1	$	(26)	$	67,599

	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