DEBT (Long-Term Debt) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total long-term debt	$ 4,036	$ 4,770
Debt issuance costs	(25)	(26)
Less: Current portion of long-term debt	3	804
Total long-term debt, net of current portion	4,033	3,966
4.75% Senior Notes due January 2020
Debt Instrument [Line Items]
Total long-term debt	$ 0	500
Debt instrument, interest rate	4.75%
Debt instrument, maturity date	Jan. 30, 2020
2.50% Senior Notes due March 2020
Debt Instrument [Line Items]
Total long-term debt	$ 0	300
Debt instrument, interest rate	2.50%
Debt instrument, maturity date	Mar. 30, 2020
4.70% Senior Notes due April 2021
Debt Instrument [Line Items]
Total long-term debt	$ 553	554
Debt instrument, interest rate	4.70%
Debt instrument, maturity date	Apr. 01, 2021
4.25% Senior Notes due April 2024
Debt Instrument [Line Items]
Total long-term debt	$ 319	308
Debt instrument, interest rate	4.25%
Debt instrument, maturity date	Apr. 01, 2024
3.50% Senior Notes due March 2025
Debt Instrument [Line Items]
Total long-term debt	$ 627	593
Debt instrument, interest rate	3.50%
Debt instrument, maturity date	Mar. 30, 2025
3.45% Senior Notes due June 2026
Debt Instrument [Line Items]
Total long-term debt	$ 513	490
Debt instrument, interest rate	3.45%
Debt instrument, maturity date	Jun. 30, 2026
4.20% Senior Notes due June 2029
Debt Instrument [Line Items]
Total long-term debt	$ 499	499
Debt instrument, interest rate	4.20%
Debt instrument, maturity date	Jun. 30, 2029
2.95% Senior Notes due June 2030
Debt Instrument [Line Items]
Total long-term debt	$ 798	798
Debt instrument, interest rate	2.95%
Debt instrument, maturity date	Jun. 30, 2030
6.95% Senior Notes due July 2037
Debt Instrument [Line Items]
Total long-term debt	$ 175	175
Debt instrument, interest rate	6.95%
Debt instrument, maturity date	Jul. 01, 2037
5.75% Senior Notes due January 2040
Debt Instrument [Line Items]
Total long-term debt	$ 245	245
Debt instrument, interest rate	5.75%
Debt instrument, maturity date	Jan. 30, 2040
4.70% Senior Notes due March 2045
Debt Instrument [Line Items]
Total long-term debt	$ 300	300
Debt instrument, interest rate	4.70%
Debt instrument, maturity date	Mar. 30, 2045
Other
Debt Instrument [Line Items]
Other	$ 32	$ 34

Contractual interest rate for funds borrowed, under the debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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