FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	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	433,200
Level 3 | Contingent Consideration | Accrued Liabilities
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	5,500	$ 6,600
Level 3 | Contingent Consideration | Other long-term liabilities
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	1,400	1,700
Recurring
Assets measured at fair value on a recurring basis
Assets fair value disclosure	64,660	5,069
Liabilities fair value disclosure	15,966	9,459
Recurring | Interest rate swap agreement
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	9,055	1,176
Recurring | Fixed-income securities
Assets measured at fair value on a recurring basis
Assets fair value disclosure	4,266	4,210
Recurring | Money market funds
Assets measured at fair value on a recurring basis
Assets fair value disclosure	60,394	859
Recurring | Contingent Consideration
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	6,911	8,283
Recurring | Quoted Prices in Active Markets (Level 1)
Assets measured at fair value on a recurring basis
Assets fair value disclosure	62,818	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	2,424	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	60,394	859
Recurring | Other Observable Inputs (Level 2)
Assets measured at fair value on a recurring basis
Assets fair value disclosure	1,842	1,830
Liabilities fair value disclosure	9,055	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	9,055	1,176
Recurring | Other Observable Inputs (Level 2) | Fixed-income securities
Assets measured at fair value on a recurring basis
Assets fair value disclosure	1,842	1,830
Recurring | Level 3
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	6,911	8,283
Recurring | Level 3 | Contingent Consideration
Assets measured at fair value on a recurring basis
Liabilities fair value disclosure	$ 6,911	$ 8,283