DEBT AND FINANCING COSTS - Schedule of Debt (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt before unamortized discount and deferred loan costs	$ 8,299	$ 8,580
Unamortized discount	(45)	(47)
Debt issuance costs	(51)	(49)
Total debt	8,203	8,484
Current maturities	(150)	(550)
Long-term debt	$ 8,053	$ 7,934

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Face (par) amount of debt instrument at time of issuance.

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Amount, after accumulated amortization, of debt discount.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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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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