INVESTMENTS

12 Months Ended

Dec. 31, 2019

Investments, Debt and Equity Securities [Abstract]

INVESTMENTS

INVESTMENTS:

Cash, cash equivalents and short-term investments:

At December 31, 2019 and 2018, the Company held cash, cash equivalents and short-term investments classified as available-for-sale securities as follows:

	December 31, 2019						December 31, 2018
	Amortized Cost			Estimated Fair Value			Amortized Cost			Estimated Fair Value
	(in thousands)
Cash and cash equivalents	$	76,521		$	76,521		$	55,501		$	55,501
Money market funds	1,058			1,058			1,265			1,265
Certificates of deposit	198,561			198,663			95,080			95,038
Government debt securities	232,357			232,604			100,449			100,478
Corporate debt securities	365,792			367,051			186,571			186,208
Total	874,289			875,897			438,866			438,490
Less amounts classified as cash and cash equivalents	(77,579		)	(77,579		)	(56,766		)	(56,766		)
Short-term investments	$	796,710		$	798,318		$	382,100		$	381,724

The Company does not intend to sell the short-term investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be at maturity.

Interest income and gains on short-term investments, net were $15.6 million and $5.6 million for the years ended December 31, 2019 and 2018, respectively. At December 31, 2019, the unrealized gains and unrealized losses were $1.9 million and $0.3 million, respectively. At December 31, 2018, the unrealized gains and unrealized losses were $0.1 million and $0.5 million, respectively. At December 31, 2019, gross unrealized losses on investments that were in a gross unrealized loss position for greater than 12 months were immaterial. These investments were not deemed to be other-than-temporarily impaired and the gross unrealized losses were recorded in OCI.

The contractual maturities of short-term investments at December 31, 2019 and 2018 were as follows:

	December 31, 2019				December 31, 2018
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(in thousands)
Due in less than one year	$	424,616	$	425,053	$	281,303	$	280,959
Due in one to three years	372,094		373,265		100,797		100,765
	$	796,710	$	798,318	$	382,100	$	381,724

Equity investments in privately-held companies:

As of December 31, 2019 and 2018, the Company held a total of $39.3 million and $40.3 million, respectively, in equity investments in privately-held companies. During the first quarter of 2019, one of the investees of the Company's equity investments in privately-held companies was acquired. As a result, the Company recorded a gain on sale of $9.1 million in the first quarter of 2019. In addition, $3.2 million of the consideration owed to the Company was held back in an escrow account as of December 31, 2019. The final amount released from escrow, if any, will be recognized as an additional gain on sale when released. During the second quarter of 2019, the Company recorded a gain of $0.4 million from the conversion of a note receivable to equity in a privately-held company.

While performing its review for impairment for the first quarter of 2019, the Company noted an observable price change related to one of its investments in a privately-held company; as a result, the Company recorded an impairment charge of $1.8 million.