Loans and finance receivables (Detail) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Receivables [Abstract]
Loans and finance receivables before allowances and discounts	$ 28,907	$ 26,289
Allowances for credit losses	(1,051)	(950)	$ (926)	$ (856)
Unamortized acquisition discounts and points	(750)	(658)
Loans and finance receivables	$ 27,106	$ 24,681

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant