DEBT - Senior Notes (Details) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2020
Debt Instrument [Line Items]
Repayments of senior notes		$ 400,000,000	$ 400,000,000	$ 0
Senior notes
Debt Instrument [Line Items]
Net proceeds from issuance of notes		$ 1,088,000,000
Debt redemption price (percent)		100.00%
Senior notes | $400 million, 2.50% due December 15, 2020
Debt Instrument [Line Items]
Repayments of senior notes	$ 400,000,000
Face amount	$ 400,000,000	$ 400,000,000
Stated interest rate (percent)	2.50%	2.50%
Senior notes | $600 million, 4.50% due April 1, 2025
Debt Instrument [Line Items]
Face amount	$ 600,000,000	$ 600,000,000			$ 600,000,000
Stated interest rate (percent)	4.50%	4.50%			4.50%
Senior notes | $500 million, 4.875% due April 1, 2030
Debt Instrument [Line Items]
Face amount	$ 500,000,000	$ 500,000,000			$ 500,000,000
Stated interest rate (percent)	4.875%	4.875%			4.875%
Senior notes | $250 million, 8.15% due June 15, 2038
Debt Instrument [Line Items]
Face amount	$ 250,000,000	$ 250,000,000
Stated interest rate (percent)	8.15%	8.15%