Loans and finance receivables - Schedule of reconciliation of allowance for credit losses on loans and finance receivables (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Allowance for Credit Loss [Abstract]
Balance at the beginning of the year	$ 1,134	$ 950	$ 856
Provision for credit losses	385	298	169
Charge-offs, net of recoveries	(172)	(114)	(75)
Balance at December 31	$ 1,347	$ 1,134	$ 950

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

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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant