DEBT SECURITIES (Tables)

9 Months Ended

Sep. 30, 2020

Investments, Debt and Equity Securities [Abstract]

Debt securities consisted of the following (in thousands):


	September 30, 2020		December 31, 2019
Commercial paper	$	63,163	$	17,152
Corporate debt securities	139,548		306,436
Securities of government sponsored entities	53,075		12,500
Total debt securities	$	255,786	$	336,088

Debt securities available for sale

The following is a summary of short-term debt securities classified as available-for-sale as of September 30, 2020 (in thousands):


	Remaining Contractual Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Estimated Fair Value
Commercial paper	Less than 1	$	63,167	$	2	$	(6)	$	63,163
Corporate debt securities	Less than 1	91,922		619		—		92,541
Securities of government-sponsored entities	Less than 1	43,081		—		—		43,081
Total maturity less than 1 year		198,170		621		(6)		198,785
Corporate debt securities	1 to 2	46,485		522		—		47,007
Securities of government-sponsored entities	1 to 2	10,000		1		(7)		9,994
Total maturity 1 to 2 years		56,485		523		(7)		57,001
Total available-for-sale securities		$	254,655	$	1,144	$	(13)	$	255,786

The following is a summary of short-term debt securities classified as available-for-sale as of December 31, 2019 (in thousands):


	Remaining Contractual Maturity (in years)	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Estimated Fair Value
Commercial paper	Less than 1	$	17,136	$	16	$	—	$	17,152
Corporate debt securities	Less than 1	191,770		582		(10)		192,342

Total maturity less than 1 year		208,906		598		(10)		209,494
Corporate debt securities	1 to 2	113,799		351		(56)		114,094
Securities of government-sponsored entities	1 to 2	12,501		—		(1)		12,500
Total maturity 1 to 2 years		126,300		351		(57)		126,594
Total available-for-sale securities		$	335,206	$	949	$	(67)	$	336,088

Schedule of securities in an unrealized loss position

The following is a summary of available-for-sale debt securities in an unrealized loss position with no credit losses reported as of September 30, 2020 (in thousands):


	Less Than 12 Months				12 Months or Greater				Total
Description of Securities	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Commercial paper	$	58,166	$	6	$	—	$	—	$	58,166	$	6
Corporate debt securities	—		—		—		—		—		—
Securities of government-sponsored entities	43,074		7		—		—		43,074		7
Total	$	101,240	$	13	$	—	$	—	$	101,240	$	13

The following is a summary of available-for-sale debt securities in an unrealized loss position with no credit losses reported as of December 31, 2019 (in thousands):


	Less Than 12 Months				12 Months or Greater				Total
Description of Securities	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Commercial paper	$	—	$	—	$	—	$	—	$	—	$	—
Corporate debt securities	74,151		64		7,509		2		81,660		66
Securities of government-sponsored entities	5,000		1		—		—		5,000		1
Total	$	79,151	$	65	$	7,509	$	2	$	86,660	$	67