Loans and finance receivables - Narrative (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregated carrying value	$ 23,238,000,000	$ 22,065,000,000
Term Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregated carrying value	1,900,000,000	1,900,000,000
Seritage Growth Properties [Member] | Term Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregated carrying value	1,440,000,000	$ 1,440,000,000
Term loan facility	$ 2,000,000,000.0
Loan expiration date	Jul. 31, 2023
Extended loan maturity date	Jul. 31, 2025
Maximum principal loan balance to extend loan maturity period	$ 800,000,000
Manufactured and Site-built Home Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percent of manufactured and site-built housing loan balances evaluated collectively for impairment	99.00%
Percent of loan balances considered to be current as to payment status	97.00%