INCOME TAXES - Foreign Earnings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Foreign pretax earnings	$ 16,700	$ 16,100	$ 13,700
Accumulated undistributed profits of non-U.S. subsidiaries considered indefinitely reinvested	10,900	$ 15,500
Additional tax liability to be provided should be undistributed earnings of foreign subsidiaries which were indefinitely invested were remitted currently	4,100
Decrease in basis differences due to treatment of country affiliate branch rather than subsidiary	4,600
Total bad debt reserved not included in deferred tax liabilities calculation	358
Deferred tax liabilities not recognized relating to bad debt reserved	$ 75