Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 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		March 31,
	Level 1		Level 2		Level 3		2017
	(In thousands)
As of March 31, 2017:
Assets
Money market deposits	$	12,731	$	—	$	—	$	12,731
Commercial paper		—		45,042		—		45,042
Corporate debt securities		—		9,504		—		9,504
Total	$	12,731	$	54,546	$	—	$	67,277

	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

	March 31, 2017
	Cost or		Gross		Gross		Total
	Amortized		Unrealized		Unrealized		Estimated
	Cost		Gains		Losses		Fair Value
	(In thousands)
Commercial paper	$	45,065	$	1	$	(23)	$	45,043
Corporate debt securities		9,503		2		(2)		9,503
Total	$	54,568	$	3	$	(25)	$	54,546

	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

Summary of available-for-sale marketable securities by contractual maturity

	March 31, 2017				December 31, 2016
	Amortized		Estimated		Amortized		Estimated
	Cost		Fair Value		Cost		Fair Value
	(In thousands)
Due in one year or less	$	53,670	$	53,648	$	54,566	$	56,585
Due in more than one year but less than five years		898		898		—		—
Total	$	54,568	$	54,546	$	54,566	$	56,585