Equipment held for lease - Narrative (Detail) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025
Leases [Abstract]
Equipment held for lease depreciation expense	$ 747	$ 749

Amount of depreciation expense for lessor's underlying asset for which right to use has been conveyed to lessee under operating lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-13

Name:	us-gaap_OperatingLeasesIncomeStatementDepreciationExpenseOnPropertySubjectToOrHeldForLease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration