DERIVATIVE INSTRUMENTS - Fair Value of Derivative Instruments By Balance Sheet Location (Details) € in Millions, SFr in Millions	Sep. 30, 2021 USD ($)	Sep. 30, 2021 EUR (€)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 21, 2020 USD ($)	Dec. 21, 2020 CHF (SFr)
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Assets	$ 33,197,000			$ 12,920,000
Total derivatives designated as hedges — Liabilities	70,018,000			136,165,000
Interest rate swap | Cash Flow Hedges | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Current notional amount	1,800,000,000			1,900,000,000
Interest rate swap | Cash Flow Hedges | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Assets	6,798,000			0
Interest rate swap | Cash Flow Hedges | Designated as Hedging Instrument | Accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Liabilities	21,095,000			22,033,000
Interest rate swap | Cash Flow Hedges | Designated as Hedging Instrument | Other liabilities
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Liabilities	40,517,000			71,736,000
Cross-currency swap
Derivatives, Fair Value [Line Items]
Current notional amount			$ 7,300,000		$ 471,600,000	SFr 420.1
Cross-currency swap | Cash Flow Hedges | Designated as Hedging Instrument | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Assets	8,587,000			7,623,000
Cross-currency swap | Cash Flow Hedges | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Assets	8,578,000			0
Cross-currency swap | Cash Flow Hedges | Designated as Hedging Instrument | Accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Liabilities	1,726,000			4,335,000
Cross-currency swap | Cash Flow Hedges | Designated as Hedging Instrument | Other liabilities
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Liabilities	6,680,000			26,728,000
Cross-currency swap | Net Investment Hedges
Derivatives, Fair Value [Line Items]
Current notional amount	52,000,000	€ 44.9
Cross-currency swap | Net Investment Hedges | Designated as Hedging Instrument | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Assets	5,345,000			5,297,000
Cross-currency swap | Net Investment Hedges | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Assets	3,889,000			0
Cross-currency swap | Net Investment Hedges | Designated as Hedging Instrument | Accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Liabilities	0			1,884,000
Cross-currency swap | Net Investment Hedges | Designated as Hedging Instrument | Other liabilities
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedges — Liabilities	$ 0			$ 9,449,000