DISPOSITIONS AND ACQUISITIONS (Net Income (Loss) from Discontinued Operations) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain (loss) on disposal									$ 57	$ (198)	$ 0
Net income (loss) from discontinued operations	$ 16	$ 3	$ 9	$ 38	$ (2)	$ (6)	$ (181)	$ (4)	66	(193)	91
Other assets	2,270				1,956				2,270	1,956
Eliminations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income (loss) from discontinued operations									0	(39)	0
TF Holdings Limited | Disposed of by Sale, Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues									13	959	1,270
Production and delivery costs									0	833	852
Depreciation, depletion and amortization									0	80	257
Interest expense allocated from parentc									0	39	28
Other costs and expenses, net									0	10	26
Income (loss) before income taxes and net gain (loss) on disposal									13	(3)	107
Net gain (loss) on disposal									57	(198)	0
Net income (loss) before income taxes									70	(201)	107
(Provision for) benefit from income taxes									(4)	8	(16)
Net income (loss) from discontinued operations									66	(193)	91
Other assets	$ 74				$ 13				74	13
TF Holdings Limited | Disposed of by Sale, Discontinued Operations | Eliminations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues									$ (13)	$ 157	$ 114