DEBT - Components of Total Indebtedness (Details) - USD ($)	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Aug. 31, 2020
Debt Instrument [Line Items]
Principal Amount	$ 8,365,968,000		$ 8,376,443,000
Carrying Amount	8,274,016,000		8,314,728,000
Less: current portion, net	223,142,000		34,150,000
Principal amount of total long-term debt, less current portion, net	8,142,826,000		8,342,293,000
Carrying amount of total long-term debt, less current portion, net	8,050,874,000		8,280,578,000
Fair value of long term debt	$ 8,000,000,000		$ 8,400,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Effective Interest Rate (as a percent)	2.63%		2.69%
Principal Amount	$ 300,000,000		$ 300,000,000
Carrying Amount	$ 300,000,000		$ 300,000,000
7.25% Senior Notes due 2022
Debt Instrument [Line Items]
Interest rate (as a percent)	7.25%
Effective Interest Rate (as a percent)	7.25%		7.25%
Principal Amount	$ 8,294,000		$ 8,294,000
Carrying Amount	$ 8,294,000		$ 8,294,000
5.75% Senior Notes due 2022
Debt Instrument [Line Items]
Interest rate (as a percent)	5.75%			5.75%
Effective Interest Rate (as a percent)	5.75%		5.75%
Principal Amount	$ 172,048,000		$ 172,048,000	$ 10,000,000
Carrying Amount	$ 172,048,000		$ 172,048,000
5.375% Senior Notes due 2023
Debt Instrument [Line Items]
Interest rate (as a percent)	5.375%
Effective Interest Rate (as a percent)	5.62%		5.62%
Principal Amount	$ 6,127,000		$ 6,127,000
Carrying Amount	$ 6,109,000		$ 6,098,000
6.00% Senior Notes due 2023
Debt Instrument [Line Items]
Interest rate (as a percent)	6.00%
Effective Interest Rate (as a percent)	6.28%		6.28%
Principal Amount	$ 56,436,000		$ 56,436,000
Carrying Amount	$ 56,167,000		$ 56,063,000
5.875% Senior Secured Notes due 2024
Debt Instrument [Line Items]
Interest rate (as a percent)	5.875%
Effective Interest Rate (as a percent)	6.14%		6.14%
Principal Amount	$ 300,000,000		$ 300,000,000
Carrying Amount	$ 297,758,000		$ 297,267,000
6.00% Senior Notes due 2025
Debt Instrument [Line Items]
Interest rate (as a percent)	6.00%
Effective Interest Rate (as a percent)	6.27%		6.27%
Principal Amount	$ 21,578,000		$ 21,578,000
Carrying Amount	$ 21,401,000		$ 21,366,000
7.50% Senior Secured Notes due 2027
Debt Instrument [Line Items]
Interest rate (as a percent)	7.50%
Effective Interest Rate (as a percent)	7.70%		7.70%
Principal Amount	$ 2,015,479,000		$ 2,015,479,000
Carrying Amount	$ 1,997,099,000		$ 1,995,142,000
9.50% Senior Secured Second Lien Notes due 2027
Debt Instrument [Line Items]
Interest rate (as a percent)	9.50%
Effective Interest Rate (as a percent)	9.68%		9.68%
Principal Amount	$ 940,590,000		$ 940,590,000
Carrying Amount	$ 933,088,000		$ 932,395,000
6.00% Senior Notes due 2028
Debt Instrument [Line Items]
Interest rate (as a percent)	6.00%
Effective Interest Rate (as a percent)	6.11%		6.11%
Principal Amount	$ 1,260,416,000		$ 1,260,416,000
Carrying Amount	$ 1,252,426,000		$ 1,251,725,000
6.125% Senior Secured Notes due 2029
Debt Instrument [Line Items]
Interest rate (as a percent)	6.125%	6.125%
Effective Interest Rate (as a percent)	6.34%
Principal Amount	$ 1,295,000,000	$ 1,295,000,000	$ 0
Carrying Amount	$ 1,278,278,000		$ 0
Term Loan Facility
Debt Instrument [Line Items]
Effective Interest Rate (as a percent)	6.12%		5.21%
Principal Amount	$ 1,990,000,000		$ 3,295,475,000
Carrying Amount	$ 1,951,348,000		$ 3,274,330,000