Loans and finance receivables - Summary of performing and non-performing home loans before discounts and allowances by year of loan origination (Detail) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, Total	$ 30,819	$ 29,700
Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2025	3,195
Loans and financing receivables by origination year, 2024	5,666
Loans and financing receivables by origination year, 2023	4,757
Loans and financing receivables by origination year, 2022	3,517
Loans and financing receivables by origination year, 2021	2,927
Loans and financing receivables by origination year, Prior	9,961
Loans and financing receivables by origination year, Total	30,023
Performing [Member] \| Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2025	3,193
Loans and financing receivables by origination year, 2024	5,651
Loans and financing receivables by origination year, 2023	4,738
Loans and financing receivables by origination year, 2022	3,499
Loans and financing receivables by origination year, 2021	2,911
Loans and financing receivables by origination year, Prior	9,899
Loans and financing receivables by origination year, Total	29,891
Non-Performing [Member] \| Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2025	2
Loans and financing receivables by origination year, 2024	15
Loans and financing receivables by origination year, 2023	19
Loans and financing receivables by origination year, 2022	18
Loans and financing receivables by origination year, 2021	16
Loans and financing receivables by origination year, Prior	62
Loans and financing receivables by origination year, Total	$ 132

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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 1: http://www.xbrl.org/2003/role/exampleRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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