INCENTIVE PLANS - Incentive Compensation Cost (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Number of shares available for grant (in shares)	41.7
Incentive compensation cost	$ 2,105	$ 2,143	$ 2,091
Restructuring Costs
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Incentive compensation cost	46
Immediately vested stock award
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Incentive compensation cost	127	101	99
Amortization of deferred cash awards, deferred cash stock units and performance stock units
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Incentive compensation cost	340	463	384
Other variable incentive compensation
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Incentive compensation cost	286	304	435
Charges for estimated awards to retirement-eligible employees | Restricted and deferred stock awards
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Incentive compensation cost	663	742	807
Amortization of restricted and deferred stock awards | Restricted and deferred stock awards
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Incentive compensation cost	$ 689	$ 533	$ 395