INCOME TAXES - Reconciliation of Tax of Income Before Income Taxes and Total Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income tax expense (benefit) at U.S. statutory rate	$ (1,016)	$ (631)	$ 201
State income tax, less federal effect	0	1	2
Taxes related to foreign operations	97	328	436
Tax credits	(13)	(6)	(13)
Tax on deemed repatriation of foreign earnings	0	0	103
Foreign tax credits	0	0	(336)
Change in U.S. tax rate	0	0	161
Net change in tax contingencies	1	1	(2)
Goodwill impairment	35	0	0
Sale of North Sea assets	0	0	(30)
Valuation allowances	965	972	118
All other, net	(5)	9	32
Total	$ 64	$ 674	$ 672