CONTINGENCIES (Asset Retirement Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of year	$ 2,771	$ 2,744	$ 2,316
Liabilities incurred	12	97	429
Settlements and revisions to cash flow estimates, net	529	(66)	56
Accretion expense	137	131	116
Dispositions	(626)	0	(61)
Spending	(188)	(132)	(101)
Other	0	(3)	(11)
Balance at end of year	2,635	2,771	2,744
Less current portion	(240)	(172)	(189)
Long-term portion	$ 2,395	$ 2,599	$ 2,555