Loans Receivable - Scheduled of loans receivable by property type (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Outstanding	$ 1,164.4	$ 1,279.4
Fair Value	$ 849.1	$ 877.8
Credit Concentration Risk \| Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
% of Fair Value	100.00%	100.00%
Office
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Outstanding	$ 823.7	$ 911.5
Fair Value	$ 515.8	$ 518.7
Office \| Credit Concentration Risk \| Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
% of Fair Value	60.80%	59.10%
Apartment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Outstanding	$ 157.7	$ 185.0
Fair Value	$ 153.8	$ 179.7
Apartment \| Credit Concentration Risk \| Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
% of Fair Value	18.10%	20.50%
Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Outstanding	$ 134.3	$ 134.3
Fair Value	$ 134.3	$ 134.3
Industrial \| Credit Concentration Risk \| Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
% of Fair Value	15.80%	15.30%
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Outstanding	$ 44.0	$ 44.0
Fair Value	$ 40.5	$ 40.5
Retail \| Credit Concentration Risk \| Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
% of Fair Value	4.80%	4.60%
Land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Outstanding	$ 4.7	$ 4.6
Fair Value	$ 4.7	$ 4.6
Land \| Credit Concentration Risk \| Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
% of Fair Value	0.50%	0.50%