Loans and finance receivables - Summary of performing and non-performing home loans before allowances and discounts, by year of loan origination (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, Total	$ 31,997	$ 29,700
Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2025	5,867
Loans and financing receivables by origination year, 2024	5,428
Loans and financing receivables by origination year, 2023	4,521
Loans and financing receivables by origination year, 2022	3,363
Loans and financing receivables by origination year, 2021	2,797
Loans and financing receivables by origination year, Prior	9,362
Loans and financing receivables by origination year, Total	31,338
Performing [Member] \| Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2025	5,861
Loans and financing receivables by origination year, 2024	5,404
Loans and financing receivables by origination year, 2023	4,492
Loans and financing receivables by origination year, 2022	3,344
Loans and financing receivables by origination year, 2021	2,780
Loans and financing receivables by origination year, Prior	9,298
Loans and financing receivables by origination year, Total	31,179
Non-Performing [Member] \| Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2025	6
Loans and financing receivables by origination year, 2024	24
Loans and financing receivables by origination year, 2023	29
Loans and financing receivables by origination year, 2022	19
Loans and financing receivables by origination year, 2021	17
Loans and financing receivables by origination year, Prior	64
Loans and financing receivables by origination year, Total	$ 159

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
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-Name Accounting Standards Codification
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-Publisher FASB
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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
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-Name Accounting Standards Codification
-Section 55
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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