Mortgage Loans - Portfolios (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	$ 42,335		$ 51,859
Mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total investment income	1,473	$ 818
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	15,568		16,516
Retail | Mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total investment income	595	359
Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	0		6,329
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	16,086		15,309
Commercial | Mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total investment income	494	210
Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	2,596		5,593
Multi-family | Mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total investment income	117	69
Office
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	3,210		3,197
Office | Mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total investment income	106	166
Hospitality
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	4,875		$ 4,915
Hospitality | Mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total investment income	$ 161	$ 14