Loans Receivable - Schedule of Loans Receivable (Details) - USD ($)	Jun. 30, 2024	Mar. 01, 2024	Feb. 29, 2024	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Unamortized discounts and fees	$ (5,128,000)			$ (131,000)
Reserve for loan losses	(9,143,000)			(2,830,000)	$ (8,280,000)
Loans receivable, net	275,478,000			218,450,000
Loans and leases receivable, remaining commitments	69,000,000
Unamortized discount		$ 5,000,000
Sunrise Senior Housing Portfolio
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans receivable, net	58,000,000			131,000,000
Loans and leases receivable, remaining commitments			$ 0	29,000,000
Secured Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, gross	200,583,000			178,678,000
Reserve for loan losses	(8,039,000)			(2,830,000)	$ (8,280,000)
CCRC resident loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, gross	53,346,000			42,733,000
Mezzanine Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, gross	$ 35,820,000			$ 0