Investments (Tables)

6 Months Ended

Jun. 30, 2019

Investments

Schedule of available-for-sale investments at fair value

	June 30, 2019
			Gross		Gross		Estimated
			Unrealized		Unrealized		Fair
(In thousands)	Cost		(Losses)		Gains		Value
Short-term investments – commercial paper	$	3,496	$	—	$	—	$	3,496
Short-term investments – U.S. treasury bills		8,991		—		2		8,993
Total short-term investments	$	12,487	$	—	$	2	$	12,489
Total investments	$	12,487	$	—	$	2	$	12,489