Investments

12 Months Ended

Dec. 31, 2019

Investments [Abstract]

Investments

2. Investments

The following table summarizes the contract maturity of the available-for-sale securities we held as of December 31, 2019:

One year or less	70	%
After one year but within two years	20	%
After two years but within three and a half years	10	%
Total	100	%

As illustrated above, at December 31, 2019, 90 percent of our available-for-sale securities had a maturity of less than two years.

All of our available-for-sale securities are available to us for use in our current operations. As a result, we categorize all of these securities as current assets even though the stated maturity of some individual securities may be one year or more beyond the balance sheet date.

At December 31, 2019, we had an ownership interest of less than 20 percent in five private companies and two public companies with which we conduct business. The privately-held companies are Atlantic Pharmaceuticals Limited, Dynacure SAS, Empirico, Inc., Seventh Sense Biosystems and Suzhou Ribo Life Science Co, Ltd.The publicly traded companies are ATL and ProQR.

The following is a summary of our investments (in thousands):

			Gross Unrealized					Estimated
December 31, 2019	Cost (1)		Gains		Losses			Fair Value
Available-for-sale securities:
Corporate debt securities (2)	$	669,665	$	1,451	$	(43	)	$	671,073
Debt securities issued by U.S. government agencies		188,216		303		(43	)		188,476
Debt securities issued by the U.S. Treasury (2)		327,670		232		(27	)		327,875
Debt securities issued by states of the U.S. and political subdivisions of the states		21,065		26		(5	)		21,086
Total securities with a maturity of one year or less		1,206,616		2,012		(118	)		1,208,510
Corporate debt securities		428,627		2,911		(43	)		431,495
Debt securities issued by U.S. government agencies		140,988		57		(117	)		140,928
Debt securities issued by the U.S. Treasury		35,822		9		(12	)		35,819
Debt securities issued by states of the U.S. and political subdivisions of the states		19,309		18		(6	)		19,321
Total securities with a maturity of more than one year		624,746		2,995		(178	)		627,563
Total available-for-sale securities	$	1,831,362	$	5,007	$	(296	)	$	1,836,073
Equity securities:
Total equity securities included in other current assets (3)	$	4,712	$	-	$	(870	)	$	3,842
Total equity securities included in deposits and other assets (4)		10,000		-		-			10,000
Total equity securities	$	14,712	$	-	$	(870	)	$	13,842
Total available-for-sale and equity securities	$	1,846,074	$	5,007	$	(1,166	)	$	1,849,915

			Gross Unrealized					Estimated
December 31, 2018	Cost (1)		Gains		Losses			Fair Value
Available-for-sale securities:
Corporate debt securities (2)	$	956,879	$	13	$	(1,858	)	$	955,034
Debt securities issued by U.S. government agencies		168,839		3		(104	)		168,738
Debt securities issued by the U.S. Treasury		244,640		15		(77	)		244,578
Debt securities issued by states of the U.S. and political subdivisions of the states (2)		63,572		—		(323	)		63,249
Total securities with a maturity of one year or less		1,433,930		31		(2,362	)		1,431,599
Corporate debt securities		299,018		194		(1,286	)		297,926
Debt securities issued by U.S. government agencies		107,789		194		(109	)		107,874
Debt securities issued by the U.S. Treasury		15,600		—		(24	)		15,576
Debt securities issued by states of the U.S. and political subdivisions of the states		16,980		—		(287	)		16,693
Total securities with a maturity of more than one year		439,387		388		(1,706	)		438,069
Total available-for-sale securities	$	1,873,317	$	419	$	(4,068	)	$	1,869,668
Equity securities:
Total equity securities included in other current assets (3)	$	1,212	$	137	$	—		$	1,349
Total available-for-sale and equity securities	$	1,874,529	$	556	$	(4,068	)	$	1,871,017

(1) We hold our available-for-sale securities at amortized cost.

(2) Includes investments classified as cash equivalents on our consolidated balance sheet.

(3) Our equity securities included in other current assets consisted of our investment in ProQR, which is a public company. We recognize our public company equity securities at fair value.

(4) Our equity securities included in deposits and other assets consisted of our investment in Empirico, which is a private company. We recognize our private company equity securities at cost minus impairments, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer on our consolidated balance sheet.

Investments we consider to be temporarily impaired at December 31, 2019 are as follows (in thousands):

			Less than 12 Months of Temporary Impairment					More than 12 Months of Temporary Impairment					Total Temporary Impairment
	Number of Investments		Estimated Fair Value		Unrealized Losses			Estimated Fair Value		Unrealized Losses			Estimated Fair Value		Unrealized Losses
Corporate debt securities		49	$	131,702	$	(75	)	$	11,840	$	(11	)	$	143,542	$	(86	)
Debt securities issued by U.S. government agencies		43		149,731		(136	)		37,041		(24	)		186,772		(160	)
Debt securities issued by the U.S. Treasury		10		84,270		(39	)		—		—			84,270		(39	)
Debt securities issued by states of the U.S. and political subdivisions of the states		11		10,241		(5	)		10,303		(6	)		20,544		(11	)
Total temporarily impaired securities		113	$	375,944	$	(255	)	$	59,184	$	(41	)	$	435,128	$	(296	)

We believe that the decline in value of our debt securities is temporary and primarily related to the change in market interest rates since purchase. We believe it is more likely than not that we will be able to hold these securities to maturity. Therefore, we anticipate full recovery of our debt securities’ amortized cost basis at maturity.