INCOME TAXES - NARRATIVE (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Worldwide effective tax rate	14.00%	243.00%	26.00%
Total deferred tax assets, after valuation allowances	$ 4,345,000,000	$ 3,703,000,000
Total deferred tax liabilities	11,402,000,000	13,364,000,000
Foreign tax credit carryforwards	4,465,000,000	4,379,000,000
General business credit carryforwards	607,000,000	443,000,000
Interest expense carryforward	668,000,000	492,000,000
Deferred foreign tax liability due to reversal of indefinite re-investment assertion	930,000,000
Additional deferred tax liability amount required	214,000,000
Unrecognized tax benefits	2,045,000,000	2,173,000,000	$ 0	$ 22,000,000
Potential benefit	2,000,000,000.0
Potential benefit, if recognized, would affect the effective tax rate on income	1,600,000,000
Benefits related to tax positions which ultimate deductibility is highly certain	84,000,000
Interest related to liabilities for unrecognized tax benefits	67,000,000
Cumulative accrued interest related to liabilities for unrecognized tax benefits	263,000,000
Interest and penalties associated with liabilities for unrecognized tax benefits		0
Low end of range
Income Tax Contingency [Line Items]
Possible decrease to unrecognized tax benefit due to settlements with taxing authorities	70,000,000
High end of range
Income Tax Contingency [Line Items]
Possible decrease to unrecognized tax benefit due to settlements with taxing authorities	80,000,000
Other current assets
Income Tax Contingency [Line Items]
Income tax receivables	110,000,000	86,000,000
Long-term receivables and other assets, net
Income Tax Contingency [Line Items]
Federal alternative minimum tax non-current receivables	24,000,000	$ 36,000,000
Federal
Income Tax Contingency [Line Items]
Operating loss carryforwards	631,000,000
Interest expense carryforward	569,000,000
Foreign
Income Tax Contingency [Line Items]
Tax credit carryforward, valuation allowance	4,400,000,000
Operating loss carryforwards	850,000,000
Operating loss carryforward, valuation allowance	795,000,000
Valuation allowance on other deferred tax assets	145,000,000
State
Income Tax Contingency [Line Items]
Tax credit carryforwards	39,000,000
Tax credit carryforward, valuation allowance	30,000,000
Operating loss carryforwards	316,000,000
Operating loss carryforward, valuation allowance	251,000,000
Interest expense carryforward	99,000,000
Valuation allowance on interest expense carryforward	$ 64,000,000