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Agreements and Transactions with Related Parties - 2019 Activity (Details) - USD ($) $ in Thousands	1 Months Ended			3 Months Ended		12 Months Ended
	Nov. 30, 2025	Sep. 30, 2025	Feb. 28, 2025	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2022
Agreements and Transactions with Related Parties
Interest income				$ 235,047	$ 240,693
Related Party
Agreements and Transactions with Related Parties
Amount invested								$ 4,200
Other Related Party Transactions \| Bridge loan, six multifamily properties
Agreements and Transactions with Related Parties
UPB converted to a mezzanine loan							$ 2,000
Other Related Party Transactions \| Related Party \| Bridge loans
Agreements and Transactions with Related Parties
Principal amount	$ 67,900
SOFR floor, percentage	2.50%
Interest income				1,100
Other Related Party Transactions \| Related Party \| Bridge loans \| Maturity Date February 2025
Agreements and Transactions with Related Parties
Variable rate, spread						3.50%
Other Related Party Transactions \| Related Party \| Bridge loans \| Maturity Date February 2025 \| One multifamily property
Agreements and Transactions with Related Parties
Principal amount						$ 35,400
Other Related Party Transactions \| Related Party \| Bridge loans \| Maturity Date July 2028
Agreements and Transactions with Related Parties
SOFR floor, percentage		6.50%
Financing receivable, fixed interest rate		0.0100
Other Related Party Transactions \| Related Party \| Bridge loan, one multifamily property \| Maturity Date July 2028
Agreements and Transactions with Related Parties
Variable rate, spread		1.00%
Other Related Party Transactions \| Related Party \| AMAC III \| Mezzanine Loans
Agreements and Transactions with Related Parties
Principal amount							7,000
Other Related Party Transactions \| Related Party \| AMAC III \| Bridge loans
Agreements and Transactions with Related Parties
Principal amount							$ 34,000
Other Related Party Transactions \| Chief executive officer \| Mezzanine Loans \| Maturity date of January 2024
Agreements and Transactions with Related Parties
Fixed rate of interest							10.00%
Other Related Party Transactions \| Chief executive officer \| Bridge loan, six multifamily properties \| Maturity date of 2019 \| Minimum
Agreements and Transactions with Related Parties
Percentage of ownership interest of related party in the entity							10.50%
Other Related Party Transactions \| Chief executive officer \| Bridge loan, six multifamily properties \| Maturity date of 2019 \| Maximum
Agreements and Transactions with Related Parties
Percentage of ownership interest of related party in the entity							12.00%
Other Related Party Transactions \| Chief executive officer \| Bridge loan, six multifamily properties \| Maturity date of September 2019
Agreements and Transactions with Related Parties
Interest income				100	100
AMAC III \| Other Related Party Transactions \| Related Party
Agreements and Transactions with Related Parties
Amount invested							$ 30,000
Ownership interest, percentage							18.00%
AMAC III \| Other Related Party Transactions \| Related Party \| Bridge loans
Agreements and Transactions with Related Parties
Payoffs and partial paydowns of principal			$ 2,000
Interest income				100	700
AMAC Holdings III LLC
Agreements and Transactions with Related Parties
Gain (loss) on investment				$ (500)	(900)
Contributions made					$ 900