Investments in Available-for-Sale Securities

12 Months Ended

Dec. 31, 2017

Available-for-sale Securities [Abstract]

Investments in Available-for-Sale Securities

Investments in Available-for-Sale Securities

The Company has invested primarily in highly liquid investment-grade corporate bonds. These investments are held in the custody of a major financial institution. These securities, along with the Company’s investments in marketable equity securities, are classified as available-for-sale securities and, accordingly, the unrealized gains and losses are recorded through other comprehensive income.

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

	December 31, 2017
										Balance Sheet
			Gross		Gross					Classification
			Unrealized		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	$	—

	December 31, 2016
										Balance Sheet
			Gross		Gross					Classification
			Unrealized		Unrealized			Fair		Short-Term		Other
	Cost Basis		Gains		Losses			Value		Investments		Assets
	(In thousands)
Available-for-sale:
Corporate notes and bonds	$	88,161	$	—	$	(89	)	$	88,072	$	88,072	$	—
Equity securities	1,749		388		—			2,137		—		2,137
Total Investments	$	89,910	$	388	$	(89	)	$	90,209	$	88,072	$	2,137

The aggregate fair value of investments with unrealized losses that had been owned for less than a year was $132.0 million and $47.6 million at December 31, 2017 and 2016, respectively. The aggregate fair value of investments with unrealized losses that have been owned for over a year was $0.0 million and $40.4 million at December 31, 2017 and 2016, respectively.

The debt securities outstanding at December 31, 2017 have maturity dates ranging from the first quarter of 2018

through the second quarter of 2019. The Company classifies its investments as current based on the nature of the investments and their availability to provide cash for use in current operations, if needed.