LONG-TERM DEBT AND LINE OF CREDIT - Additional Information (Details) - USD ($)	1 Months Ended							3 Months Ended
	Oct. 30, 2020	Sep. 30, 2020	May 31, 2020	Mar. 31, 2020	Jan. 31, 2020	Mar. 31, 2019	Feb. 28, 2019	Sep. 30, 2020	Mar. 31, 2019	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt outstanding		$ 5,974,000,000						$ 5,974,000,000		$ 6,377,000,000
Pretax charge related to early extinguishment of debt			$ 11,000,000					23,000,000	$ 12,000,000
Proceeds from debt, net of issuance costs									$ 739,000,000
Borrowings on line of credit (Note 9)		0						0		$ 230,000,000
Senior Unsecured Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity					$ 1,500,000,000
Line of credit expiration date					Jan. 31, 2025
Line of credit expiration period					5 years
4.625% Notes Due in September 2023
Debt Instrument [Line Items]
Long-term debt outstanding		500,000,000						500,000,000
Long-term debt book value		$ 498,000,000						$ 498,000,000
4.625% Notes Due in September 2023 | Subsequent Event
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	4.625%
Debt, maturity date	2023-09
Debt, early redemption maturity date	2020-12
Expected redemption price	$ 560,000,000
3.25% Notes Due in March 2023
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		3.25%						3.25%
Debt, maturity date		2023-03
Repayments of debt		$ 325,000,000
4.00 percent due in April 2030
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				4.00%
Debt, maturity date				2030-04
Debt issued				$ 750,000,000
Proceeds from debt, net of issuance costs				$ 732,000,000
4.70 percent due 2021
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			4.70%
Debt, maturity date			2021-03
Repayments of debt			$ 569,000,000
4.00 percent due in November 2029
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage							4.00%
Debt, maturity date							2029-11
Debt issued							$ 750,000,000
7.38 percent due in October 2019
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage						7.38%			7.38%
Debt, maturity date						2019-10
Repayments of debt						$ 500,000,000