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LONG-TERM DEBT - Long-Term Debt by Types and Interest Rates (Includes Current Portion) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term debt	$ 0
Other	1	$ 1
Long-term debt, before unamortized discounts	4,896	4,896
Less unamortized discounts	(5)	(5)
Total	4,891	4,891
Portion due within one year	0	0
6.95% debentures due 2017
Debt Instrument [Line Items]
Long-term debt	$ 281	281
Debt, interest rate	6.95%
Debt, maturity date	Dec. 31, 2017
7.00% debentures due 2018
Debt Instrument [Line Items]
Long-term debt	$ 62	62
Debt, interest rate	7.00%
Debt, maturity date	Dec. 31, 2018
7.375% notes due 2019
Debt Instrument [Line Items]
Long-term debt	$ 500	500
Debt, interest rate	7.375%
Debt, maturity date	Dec. 31, 2019
Variable rate term loan credit facility matures 2020
Debt Instrument [Line Items]
Long-term debt	$ 550		$ 550
Debt, maturity date	Dec. 31, 2020
9.00% debentures due 2021
Debt Instrument [Line Items]
Long-term debt	$ 150	150
Debt, interest rate	9.00%
Debt, maturity date	Dec. 31, 2021
7.125% debentures due 2023
Debt Instrument [Line Items]
Long-term debt	$ 191	191
Debt, interest rate	7.125%
Debt, maturity date	Dec. 31, 2023
4.625% notes due 2023
Debt Instrument [Line Items]
Long-term debt	$ 500		$ 500
Debt, interest rate	4.625%
Debt, maturity date	Dec. 31, 2023
8.50% debentures due 2025
Debt Instrument [Line Items]
Long-term debt	$ 300	300
Debt, interest rate	8.50%
Debt, maturity date	Dec. 31, 2025
7.95% debentures due 2025
Debt Instrument [Line Items]
Long-term debt	$ 136	136
Debt, interest rate	7.95%
Debt, maturity date	Dec. 31, 2025
7.70% debentures due 2026
Debt Instrument [Line Items]
Long-term debt	$ 150	150
Debt, interest rate	7.70%
Debt, maturity date	Dec. 31, 2026
7.35% debentures due 2026
Debt Instrument [Line Items]
Long-term debt	$ 62	62
Debt, interest rate	7.35%
Debt, maturity date	Dec. 31, 2026
7.85% debentures due 2026
Debt Instrument [Line Items]
Long-term debt	$ 100	100
Debt, interest rate	7.85%
Debt, maturity date	Dec. 31, 2026
6.95% debentures due 2027
Debt Instrument [Line Items]
Long-term debt	$ 300	300
Debt, interest rate	6.95%
Debt, maturity date	Dec. 31, 2027
7.375% debentures due 2032
Debt Instrument [Line Items]
Long-term debt	$ 1,250	1,250
Debt, interest rate	7.375%
Debt, maturity date	Dec. 31, 2032
6.875% debentures due 2033
Debt Instrument [Line Items]
Long-term debt	$ 275	275
Debt, interest rate	6.875%
Debt, maturity date	Dec. 31, 2033
Industrial revenue bonds, rates from 6.7% to 6.8%, due 2022
Debt Instrument [Line Items]
Long-term debt	$ 88	$ 88
Debt, interest rate minimum	6.70%
Debt, interest rate maximum	6.80%
Debt, maturity date	Dec. 31, 2022