FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2022

FAIR VALUE MEASUREMENTS [Abstract]

Fair Value of Assets and Liabilities Measured on Recurring Basis

(In thousands)	Balance at March 31, 2022		Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	61,945	$	44,491	$	17,454	$	—
Municipal bonds		140,383		—		140,383		—
Corporate debt securities		480,419		—		480,419		—
Commercial paper		36,209		—		36,209		—
Asset-backed securities		106,720		—		106,720		—
Government, federal agency, and other sovereign obligations		26,655		—		26,655		—
Liabilities:
Business acquisition liabilities		68,036		—		—		68,036

(In thousands)	Balance at December 31, 2021		Level 1		Level 2		Level 3
Assets:
Cash equivalents	$	26,684	$	3,768	$	22,916	$	—
Municipal bonds		157,247		—		157,247		—
Corporate debt securities		430,996		—		430,996		—
Commercial paper		38,253		—		38,253		—
Asset-backed securities		140,651		—		140,651		—
Government, federal agency, and other sovereign obligations		45,706		—		45,706		—
Liabilities:
Business acquisition liabilities		70,525		—		—		70,525

Significant Unobservable Inputs in Valuation Techniques

Unobservable input	Range			Weighted Average*
Revenue risk premium	2.4%	-	4.9%	3.0%
Revenue volatility	14.0%	-	15.8%	14.8%
Discount rate	1.2%	-	8.5%	3.3%
Projected year of payment	2022	-	2031

* The weighted average rates were calculated based on the relative fair value of each business acquisition liability.

Changes in Carrying Value of Business Acquisition Liabilities

	Three Months Ended
	March 31,
(In thousands)	2022		2021
Beginning balance	$	70,525	$	37,270
Contingent cash payments		(2,412)		(1,492)
Contingent RSU grants		(196)		(163)
Changes in fair value of business acquisition liabilities		(263)		258
Contractual payable reclassification		382		148
Ending balance	$	68,036	$	36,021