Financing Receivables - By Portfolio Segment (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) class	Dec. 31, 2023 USD ($) class
Financing receivables
Amortized cost	$ 10,827	$ 12,716
Allowance for credit losses:
Allowance for credit losses, beginning balance	156
Allowance for credit losses, ending balance	$ 131	$ 156
Client Financing Receivables
Financing receivables
Number of classes of financing receivable | class	3	3
Amortized cost	$ 9,643	$ 10,863
Allowance for credit losses:
Allowance for credit losses, beginning balance	150	168
Write-offs	(2)	(18)
Recoveries	1	5
Additions/(releases)	(16)	(12)
Other	(7)	8
Allowance for credit losses, ending balance	126	150
Client Financing Receivables | Americas
Financing receivables
Amortized cost	5,731	6,488
Allowance for credit losses:
Allowance for credit losses, beginning balance	92	88
Write-offs	(1)	(9)
Recoveries	0	0
Additions/(releases)	(8)	5
Other	(7)	7
Allowance for credit losses, ending balance	75	92
Client Financing Receivables | Europe/Middle East/Africa
Financing receivables
Amortized cost	2,531	3,007
Allowance for credit losses:
Allowance for credit losses, beginning balance	48	60
Write-offs	(1)	(1)
Recoveries	0	2
Additions/(releases)	(6)	(14)
Other	0	1
Allowance for credit losses, ending balance	41	48
Client Financing Receivables | Asia Pacific
Financing receivables
Amortized cost	1,381	1,368
Allowance for credit losses:
Allowance for credit losses, beginning balance	11	20
Write-offs	0	(8)
Recoveries	0	3
Additions/(releases)	(2)	(4)
Other	0	(1)
Allowance for credit losses, ending balance	$ 10	$ 11