LONG-TERM DEBT AND LEASE OBLIGATIONS - Schedule of Debt (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
LONG-TERM DEBT AND LEASE OBLIGATIONS
Capital leases and mortgage notes	$ 818	$ 852
Unamortized note discounts and premiums	(232)	(263)
Total long-term debt	14,507	14,510
Less current portion	184	127
Long-term debt, net of current portion	$ 14,323	$ 14,383
5%, due 2019
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	5.00%	5.00%
Carrying amount	$ 1,100	$ 1,100
5 1/2%, due 2019
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	5.50%	5.50%
Carrying amount	$ 500	$ 500
6 3/4%, due 2020
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	6.75%	6.75%
Carrying amount	$ 300	$ 300
8%, due 2020
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	8.00%	8.00%
Carrying amount	$ 750	$ 750
8 1/8%, due 2022
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	8.125%	8.125%
Carrying amount	$ 2,800	$ 2,800
6 3/4%, due 2023
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	6.75%	6.75%
Carrying amount	$ 1,900	$ 1,900
6 7/8%, due 2031
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	6.875%	6.875%
Carrying amount	$ 430	$ 430
6 1/4%, due 2018
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	6.25%	6.25%
Carrying amount	$ 1,041	$ 1,041
4 3/4%, due 2020
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	4.75%	4.75%
Carrying amount	$ 500	$ 500
6%, due 2020
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	6.00%	6.00%
Carrying amount	$ 1,800	$ 1,800
Floating % due 2020
LONG-TERM DEBT AND LEASE OBLIGATIONS
Carrying amount	$ 900	$ 900
4 1/2%, due 2021
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	4.50%	4.50%
Carrying amount	$ 850	$ 850
4 3/8%, due 2021
LONG-TERM DEBT AND LEASE OBLIGATIONS
Interest rate, stated percentage	4.375%	4.375%
Carrying amount	$ 1,050	$ 1,050

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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

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