Loans and finance receivables (Detail) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Receivables [Abstract]
Loans and finance receivables before allowances and discounts	$ 30,186	$ 29,700
Allowances for credit losses	(1,276)	(1,134)	$ (973)	$ (950)
Unamortized acquisition discounts and points	(779)	(768)
Loans and finance receivables	$ 28,131	$ 27,798

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