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, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, Total	$ 23,238	$ 22,065
Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2022	3,323
Loans and financing receivables by origination year, 2021	3,811
Loans and financing receivables by origination year, 2020	2,979
Loans and financing receivables by origination year, 2019	2,105
Loans and financing receivables by origination year, 2018	1,594
Loans and financing receivables by origination year, Prior	7,523
Loans and financing receivables by origination year, Total	21,335
Performing [Member] | Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2022	3,322
Loans and financing receivables by origination year, 2021	3,807
Loans and financing receivables by origination year, 2020	2,972
Loans and financing receivables by origination year, 2019	2,098
Loans and financing receivables by origination year, 2018	1,588
Loans and financing receivables by origination year, Prior	7,480
Loans and financing receivables by origination year, Total	21,267
Non-Performing [Member] | Manufactured Housing Loan Balances [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and financing receivables by origination year, 2022	1
Loans and financing receivables by origination year, 2021	4
Loans and financing receivables by origination year, 2020	7
Loans and financing receivables by origination year, 2019	7
Loans and financing receivables by origination year, 2018	6
Loans and financing receivables by origination year, Prior	43
Loans and financing receivables by origination year, Total	$ 68