FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 19, 2019
Assets measured at fair value on a recurring basis
Initial notional amount		$ 500,000
Equity securities without readily determinable fair value
Investment in privately held company				$ 7,900
Interest rate swap agreement
Assets measured at fair value on a recurring basis
Initial notional amount		$ 500,000
Other Observable Inputs (Level 2) | Variable-rate debt
Equity securities without readily determinable fair value
Variable rate	$ 437,700
Level 3 | Contingent Consideration | Accrued Liabilities
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	2,700		$ 6,600
Level 3 | Contingent Consideration | Other long-term liabilities
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure			1,700
Recurring
Assets measured at fair value on a recurring basis
Assets fair value disclosure	64,701		5,069
Liabilities fair value disclosure	15,845		9,459
Recurring | Interest rate swap agreement
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	13,188		1,176
Recurring | Fixed-income securities
Assets measured at fair value on a recurring basis
Assets fair value disclosure	4,359		4,210
Recurring | Money market funds
Assets measured at fair value on a recurring basis
Assets fair value disclosure	60,342		859
Recurring | Contingent Consideration
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	2,657		8,283
Recurring | Quoted Prices in Active Markets (Level 1)
Assets measured at fair value on a recurring basis
Assets fair value disclosure	62,760		3,239
Recurring | Quoted Prices in Active Markets (Level 1) | Fixed-income securities
Assets measured at fair value on a recurring basis
Assets fair value disclosure	2,418		2,380
Recurring | Quoted Prices in Active Markets (Level 1) | Money market funds
Assets measured at fair value on a recurring basis
Assets fair value disclosure	60,342		859
Recurring | Other Observable Inputs (Level 2)
Assets measured at fair value on a recurring basis
Assets fair value disclosure	1,941		1,830
Liabilities fair value disclosure	13,188		1,176
Recurring | Other Observable Inputs (Level 2) | Interest rate swap agreement
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	13,188		1,176
Recurring | Other Observable Inputs (Level 2) | Fixed-income securities
Assets measured at fair value on a recurring basis
Assets fair value disclosure	1,941		1,830
Recurring | Level 3
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	2,657		8,283
Recurring | Level 3 | Contingent Consideration
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	$ 2,657		$ 8,283