FINANCIAL INSTRUMENTS (Summary of Fair Value of Financial Instruments) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Cash Equivalents, at Carrying Value	$ 1,464	$ 628
Cash Equivalents, Accumulated Gross Unrealized Loss, Before Tax	0	0
Cash Equivalents, Accumulated Gross Unrealized Loss, Before Tax	0	0
Cash Equivalents, Fair Value	1,464	628
Total, Amortized Cost	1,495	1,477
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	154	113
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(15)	(21)
Debt Securities, Available-for-sale	1,634	1,569
Equity securities	40	15
Other Investments and Securities, at Cost	1,501	1,487
Other Investments and Securities, Accumulated Gross Unrealized Gain, Before Tax	188	119
Other Investments and Securities, Accumulated Gross Unrealized Loss, Before Tax	(15)	(22)
Cash Equivalents, Marketable Securities and Other Investments, Amortized Cost Basis	3,010	2,136
Cash Equivalents, Marketable Securities and Other Investments, Accumulated Gross Unrealized Gain, Before Tax	188	119
Cash Equivalents, Marketable Securities and Other Investments, Accumulated Gross Unrealized Loss, Before Tax	(15)	(22)
Cash Equivalents, Marketable Securities and Other Investments, Fair Value	3,183	2,233
Long-term Debt	(16,951)	(16,410)
Long Term Debt, Accumulated Gross Unrealized Gain, Before Tax	6	7
Long Term Debt, Accumulated Gross Unrealized Loss, Before Tax	(3,659)	(2,258)
Long-term debt	(20,604)	(18,661)
Derivative Assets (Liabilities), Accumulated Gross Unrealized Gain, Before Tax	173	168
Derivative Assets (Liabilities), Accumulated Gross Unrealized Loss, Before Tax	(350)	(419)
Derivative Assets (Liabilities), at Fair Value, Net	(177)	(251)
Long Term Debt, Accumulated Fair Value Adjustment	69	1
Derivative, Amount of Hedged Item	3,314	3,490
Investments carried at fair value	1,674	1,584
Interest rates 6
Debt Securities, Available-for-sale [Line Items]
Derivative Assets (Liabilities), Accumulated Gross Unrealized Gain, Before Tax	41	8
Derivative Assets (Liabilities), Accumulated Gross Unrealized Loss, Before Tax	(182)	(283)
Derivative Assets (Liabilities), at Fair Value, Net	(141)	(275)
Foreign currency
Debt Securities, Available-for-sale [Line Items]
Derivative Assets (Liabilities), Accumulated Gross Unrealized Gain, Before Tax	69	101
Derivative Assets (Liabilities), Accumulated Gross Unrealized Loss, Before Tax	(84)	(21)
Derivative Assets (Liabilities), at Fair Value, Net	(15)	80
Commodities
Debt Securities, Available-for-sale [Line Items]
Derivative Assets (Liabilities), Accumulated Gross Unrealized Gain, Before Tax	63	59
Derivative Assets (Liabilities), Accumulated Gross Unrealized Loss, Before Tax	(84)	(115)
Derivative Assets (Liabilities), at Fair Value, Net	(21)	(56)
Government debt
Debt Securities, Available-for-sale [Line Items]
Total, Amortized Cost	673	533
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	35	33
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(10)	(11)
Debt Securities, Available-for-sale	698	555
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Total, Amortized Cost	822	944
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	119	80
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(5)	(10)
Debt Securities, Available-for-sale	936	1,014
Equity securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	6	10
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	34	6
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax	0	(1)
Equity securities	40	15
Held-to-maturity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Cash Equivalents, at Carrying Value	980	220
Cash Equivalents, Accumulated Gross Unrealized Loss, Before Tax	0	0
Cash Equivalents, Accumulated Gross Unrealized Loss, Before Tax	0	0
Cash Equivalents, Fair Value	980	220
Money Market Funds [Member]
Debt Securities, Available-for-sale [Line Items]
Cash Equivalents, at Carrying Value	484	408
Cash Equivalents, Accumulated Gross Unrealized Loss, Before Tax	0	0
Cash Equivalents, Accumulated Gross Unrealized Loss, Before Tax	0	0
Cash Equivalents, Fair Value	484	408
Marketable securities 2
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis, Current	45	21
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, Current, before Tax	0	0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, Current, before Tax	0	0
Debt Securities, Available-for-sale, Current	$ 45	$ 21