DEBT - Debt Refinancing Transactions Narrative (Details) - USD ($)	1 Months Ended		3 Months Ended			9 Months Ended
	Mar. 31, 2021	Jun. 30, 2020	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Feb. 28, 2021	Dec. 31, 2020	Aug. 31, 2020
Debt Instrument [Line Items]
Repayments of debt		$ 47,200,000
Unamortized discount (premium) and debt issuance costs, net		$ 31,100,000
Principal amount			$ 8,365,968,000			$ 8,365,968,000			$ 8,376,443,000
Loss on extinguishment of debt			0		$ 0	13,753,000	$ 0
Debt issuance costs, gross			56,700,000			56,700,000
5.75% Senior Notes due 2022
Debt Instrument [Line Items]
Principal amount			$ 172,048,000			$ 172,048,000			172,048,000	$ 10,000,000
Interest rate (as a percent)			5.75%			5.75%				5.75%
Term Loan Facility
Debt Instrument [Line Items]
Principal amount			$ 1,990,000,000			$ 1,990,000,000			3,295,475,000
Long-term debt, gross								$ 3,295,500,000
Proceeds from issuance of debt	$ 2,000,000,000
Extinguishment of debt, amount						1,295,000,000
Loss on extinguishment of debt						7,800,000
Debt issuance costs, gross			29,200,000			29,200,000
6.125% Senior Secured Notes due 2029
Debt Instrument [Line Items]
Principal amount	$ 1,295,000,000		$ 1,295,000,000	$ 1,295,000,000		$ 1,295,000,000			0
Interest rate (as a percent)	6.125%		6.125%	6.125%		6.125%
Loss on extinguishment of debt						$ 6,000,000
Debt issuance costs, gross			$ 17,600,000			17,600,000
6.125% Senior Secured Notes due 2029 | Selling, general and administrative
Debt Instrument [Line Items]
Loss on extinguishment of debt					$ 31,100,000	3,900,000	$ 31,100,000
Revolving Credit Facility
Debt Instrument [Line Items]
Unamortized discount (premium) and debt issuance costs, net				$ 2,100,000
Principal amount			$ 300,000,000			$ 300,000,000			$ 300,000,000
Debt instrument, extended maturity modification, amount	$ 675,300,000			$ 675,300,000