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, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, Total	$ 23,442	$ 22,065
Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2022	4,272
Loans and financing receivables by origination year, 2021	3,703
Loans and financing receivables by origination year, 2020	2,892
Loans and financing receivables by origination year, 2019	2,045
Loans and financing receivables by origination year, 2018	1,551
Loans and financing receivables by origination year, Prior	7,247
Loans and financing receivables by origination year, Total	21,710
Performing [Member] | Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2022	4,268
Loans and financing receivables by origination year, 2021	3,696
Loans and financing receivables by origination year, 2020	2,883
Loans and financing receivables by origination year, 2019	2,037
Loans and financing receivables by origination year, 2018	1,544
Loans and financing receivables by origination year, Prior	7,205
Loans and financing receivables by origination year, Total	21,633
Non-Performing [Member] | Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2022	4
Loans and financing receivables by origination year, 2021	7
Loans and financing receivables by origination year, 2020	9
Loans and financing receivables by origination year, 2019	8
Loans and financing receivables by origination year, 2018	7
Loans and financing receivables by origination year, Prior	42
Loans and financing receivables by origination year, Total	$ 77