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DEBT - Tabular Disclosure - Notes and Debentures and Other (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 19, 2019	Dec. 31, 2018	Apr. 16, 2018	Jun. 27, 2017	Jun. 21, 2017
Debt
Other	$ 30		$ 38
Debt Issuance Costs, Net	(14)		(17)
Total long-term debt, current and non-current	2,773		2,979
Less: Current portion	2		8
Total long-term debt	2,771		2,971
6.625% Notes and Debentures Due 15 April 2018
Debt
Interest rate (as a percent)				6.625%
7.125% Notes and Debentures Due 15 March 2020 \| Senior notes and debentures
Debt
Notes and debentures	$ 0		201
Interest rate (as a percent)	7.125%	7.125%			7.125%
3.5% Notes and Debentures Due April 1, 2021
Debt
Interest rate (as a percent)	3.50%
3.5% Notes and Debentures Due April 1, 2021 \| Senior notes and debentures
Debt
Notes and debentures	$ 399		399
5.95% Notes and Debentures Due 15 March 2022 \| Senior notes and debentures
Debt
Notes and debentures	$ 326		326
Interest rate (as a percent)	5.95%
4.45% Notes and Debentures Due 1 April 2025 \| Senior notes and debentures
Debt
Notes and debentures	$ 500		500
Interest rate (as a percent)	4.45%
4.375% Notes and Debentures Due April 1, 2026
Debt
Interest rate (as a percent)	4.375%
4.375% Notes and Debentures Due April 1, 2026 \| Senior notes and debentures
Debt
Notes and debentures	$ 498		498
3.5% Notes and Debentures Due November 15, 2027
Debt
Interest rate (as a percent)	3.50%
3.5% Notes and Debentures Due November 15, 2027 \| Senior notes and debentures
Debt
Notes and debentures	$ 300		300
Interest rate (as a percent)						3.50%
7.75% Notes and Debentures Due 1 August 2029 \| Senior notes and debentures
Debt
Notes and debentures	$ 235		235
Interest rate (as a percent)	7.75%				7.75%
6.5% Notes and Debentures Due 15 August 2032 \| Senior notes and debentures
Debt
Notes and debentures	$ 200		200
Interest rate (as a percent)	6.50%				6.50%
4.5% Notes and Debentures Due May 15, 2047 \| Senior notes and debentures
Debt
Notes and debentures	$ 299		$ 299
Interest rate (as a percent)	4.50%					4.50%