MARKETABLE SECURITIES (Tables)

12 Months Ended

Dec. 31, 2021

Marketable Securities Abstract

Available-for-sale Securities

Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2021, were as follows:

	Amortized		Gross Unrealized				Estimated Fair
(In thousands)	Cost		Gains		Losses		Market Value
Investments due in 3 months or less:
Commercial paper	$	89,965	$	—	$	—	$	89,965
Corporate securities		7,285		—		(3)		7,282
Total		97,250		—		(3)		97,247
Investments due in 4-12 months:
Corporate securities		25,054		—		(42)		25,012
Total		25,054		—		(42)		25,012
Investments due in 12 months or greater:
Corporate securities		251,096		21		(1,141)		249,976
Total		251,096		21		(1,141)		249,976
Total marketable securities	$	373,400	$	21	$	(1,186)	$	372,235

Amortized cost and estimated fair market value of marketable securities classified as available-for-sale (excluding cash equivalents) at December 31, 2020, were as follows:

	Amortized		Gross Unrealized				Estimated Fair
(In thousands)	Cost		Gains		Losses		Market Value
Investments due in 3 months or less:
Commercial paper	$	43,660	$	—	$	—	$	43,660
Corporate securities		19,846		44		—		19,890
Total		63,506		44		—		63,550
Investments due in 4-12 months:
Corporate securities		125,922		846		—		126,768
Total		125,922		846		—		126,768
Total marketable securities	$	189,428	$	890	$	—	$	190,318

Available-for-sale Securities in an Unrealized Loss Position

	Less Than 12 Months				12 Months or Longer				Total
	Estimated		Gross		Estimated		Gross		Estimated		Gross
	Fair Market		Unrealized		Fair Market		Unrealized		Fair Market		Unrealized
(In thousands)	Value		Losses		Value		Losses		Value		Losses
Corporate securities	$	274,380	$	(1,186)	$	—	$	—	$	274,380	$	(1,186)
Total marketable securities	$	274,380	$	(1,186)	$	—	$	—	$	274,380	$	(1,186)