DISCONTINUED OPERATIONS, SIGNIFICANT DISPOSALS AND OTHER BUSINESS EXITS - Wind Down Charges (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended		12 Months Ended	22 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Jun. 30, 2024
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	$ 36	$ 225	$ 781	$ 0	$ 261	$ 0	$ 781
Russian Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	2							$ 67
Estimated additional charges	54				54			54
Russian Operations | All Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	2							57
Estimated additional charges	53				53			53
Russian Operations | Services, Markets and Banking
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	0							10
Estimated additional charges	1				1			1
Severance
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	39	$ 171					$ 687
Severance | Russian Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	2							48
Estimated additional charges	21				21			21
Severance | Russian Operations | All Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	2							38
Estimated additional charges	20				20			20
Severance | Russian Operations | Services, Markets and Banking
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	0							10
Estimated additional charges	1				1			1
Vendor termination and other costs | Russian Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	0							19
Estimated additional charges	33				33			33
Vendor termination and other costs | Russian Operations | All Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	0							19
Estimated additional charges	33				33			33
Vendor termination and other costs | Russian Operations | Services, Markets and Banking
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	0							0
Estimated additional charges	$ 0				$ 0			$ 0