Loans Receivable, Net - Overall Statistics for Loans Receivable Portfolio Footnotes (Detail)	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of portfolio	100.00%	100.00%
Floating Rate Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of portfolio	99.50%	99.40%
Fixed Rate Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of portfolio	0.50%	0.60%
Prepayment Restrictions Including Yield Maintenance Lock Out Provisions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of portfolio	56.00%	31.00%
Without Prepayment Restrictions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of portfolio	44.00%	69.00%