Financing Receivables - By Portfolio Segment (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) class	Dec. 31, 2023 USD ($) class
Financing receivables
Amortized cost	$ 10,593	$ 12,716
Allowance for credit losses:
Allowance for credit losses, beginning balance	156
Allowance for credit losses, ending balance	$ 145	$ 156
Client Financing Receivables
Financing receivables
Number of classes of financing receivable | class	3	3
Amortized cost	$ 9,508	$ 10,863
Allowance for credit losses:
Allowance for credit losses, beginning balance	150	168
Write-offs	0	(18)
Recoveries	0	5
Additions/(releases)	(10)	(12)
Other	(1)	8
Allowance for credit losses, ending balance	139	150
Client Financing Receivables | Americas
Financing receivables
Amortized cost	5,722	6,488
Allowance for credit losses:
Allowance for credit losses, beginning balance	92	88
Write-offs	0	(9)
Recoveries	0	0
Additions/(releases)	(10)	5
Other	0	7
Allowance for credit losses, ending balance	82	92
Client Financing Receivables | Europe/Middle East/Africa
Financing receivables
Amortized cost	2,511	3,007
Allowance for credit losses:
Allowance for credit losses, beginning balance	48	60
Write-offs	0	(1)
Recoveries	0	2
Additions/(releases)	0	(14)
Other	(1)	1
Allowance for credit losses, ending balance	46	48
Client Financing Receivables | Asia Pacific
Financing receivables
Amortized cost	1,275	1,368
Allowance for credit losses:
Allowance for credit losses, beginning balance	11	20
Write-offs	0	(8)
Recoveries	0	3
Additions/(releases)	1	(4)
Other	0	(1)
Allowance for credit losses, ending balance	$ 12	$ 11