Investments in Available-for-Sale Securities (Tables)

3 Months Ended

Mar. 31, 2018

Available-for-sale Securities [Abstract]

Available-for-sale Securities

The Company’s investments in available-for-sale marketable securities are as follows:

	March 31, 2018
										Balance Sheet
										Classification
			Gross Unrealized					Fair		Short-Term		Other
	Cost Basis		Gains		Losses			Value		Investments		Assets
	(In thousands)
Available-for-sale:
U.S. government and agency securities	$	56,798	$	—	$	(121	)	$	56,677	$	56,677	$	—
Corporate notes and bonds	88,512		—		(537		)	87,975		87,975		—
Total Investments	$	145,310	$	—	$	(658	)	$	144,652	$	144,652	$	—

	December 31, 2017
										Balance Sheet
										Classification
			Gross Unrealized					Fair		Short-Term		Other
	Cost Basis		Gains		Losses			Value		Investments		Assets
	(In thousands)
Available-for-sale:
U.S. government and agency securities	$	64,151	$	22	$	(73	)	$	64,100	$	64,100	$	—
Corporate notes and bonds	92,038		—		(292		)	91,746		91,746		—
Total Investments	$	156,189	$	22	$	(365	)	$	155,846	$	155,846	$	—