DISCONTINUED OPERATIONS, SIGNIFICANT DISPOSALS AND OTHER BUSINESS EXITS - Wind Down Charges (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended		12 Months Ended	25 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Sep. 30, 2024
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	$ 9	$ 36	$ 225	$ 0	$ 270	$ 0	$ 781
Russian Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	4							$ 71
Estimated additional charges	42				42			42
Russian Operations | All Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	4							61
Estimated additional charges	41				41			41
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	9	$ 39	$ 171				$ 687
Severance | Russian Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	3							51
Estimated additional charges	20				20			20
Severance | Russian Operations | All Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Restructuring	3							41
Estimated additional charges	19				19			19
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	1							20
Estimated additional charges	22				22			22
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	1							20
Estimated additional charges	22				22			22
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