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	Sep. 30, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, Total	$ 28,907	$ 26,289
Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2024	5,172
Loans and financing receivables by origination year, 2023	5,100
Loans and financing receivables by origination year, 2022	3,748
Loans and financing receivables by origination year, 2021	3,130
Loans and financing receivables by origination year, 2020	2,418
Loans and financing receivables by origination year, Prior	8,479
Loans and financing receivables by origination year, Total	28,047
Performing [Member] \| Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2024	5,170
Loans and financing receivables by origination year, 2023	5,085
Loans and financing receivables by origination year, 2022	3,729
Loans and financing receivables by origination year, 2021	3,114
Loans and financing receivables by origination year, 2020	2,404
Loans and financing receivables by origination year, Prior	8,425
Loans and financing receivables by origination year, Total	27,927
Non-Performing [Member] \| Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2024	2
Loans and financing receivables by origination year, 2023	15
Loans and financing receivables by origination year, 2022	19
Loans and financing receivables by origination year, 2021	16
Loans and financing receivables by origination year, 2020	14
Loans and financing receivables by origination year, Prior	54
Loans and financing receivables by origination year, Total	$ 120

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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