Financing Receivables - By Portfolio Segment (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022 USD ($) item	Dec. 31, 2021 USD ($) item
Financing receivables
Number of classes of financing receivable | item	3	3
Amortized Cost	$ 11,957.0	$ 13,640.0
Allowance for credit losses:
Allowance for credit losses, beginning balance	201.0
Allowance for credit losses, ending balance	179.0	201.0
Client Financing Receivables
Financing receivables
Amortized Cost	11,349.0	12,397.0
Allowance for credit losses:
Allowance for credit losses, beginning balance	195.0	255.0
Write-offs	(17.0)	(17.0)
Recoveries	1.0	1.0
Additions/(releases)	(8.0)	(38.0)
Other	2.0	(7.0)
Allowance for credit losses, ending balance	172.0	195.0
Client Financing Receivables | Americas
Financing receivables
Amortized Cost	6,116.0	6,573.0
Allowance for credit losses:
Allowance for credit losses, beginning balance	111.0	141.0
Write-offs	(15.0)	(8.0)
Recoveries	1.0	0.0
Additions/(releases)	(5.0)	(19.0)
Other	3.0	(3.0)
Allowance for credit losses, ending balance	95.0	111.0
Client Financing Receivables | EMEA
Financing receivables
Amortized Cost	3,333.0	3,793.0
Allowance for credit losses:
Allowance for credit losses, beginning balance	61.0	77.0
Write-offs	0.0	(2.0)
Recoveries	0.0	0.0
Additions/(releases)	(3.0)	(11.0)
Other	(1.0)	(3.0)
Allowance for credit losses, ending balance	56.0	61.0
Client Financing Receivables | Asia Pacific
Financing receivables
Amortized Cost	1,900.0	2,031.0
Allowance for credit losses:
Allowance for credit losses, beginning balance	23.0	37.0
Write-offs	(2.0)	(7.0)
Recoveries	0.0	1.0
Additions/(releases)	(1.0)	(7.0)
Other	0.0	0.0
Allowance for credit losses, ending balance	$ 21.0	$ 23.0