Loans and Investments - Investment Portfolio and Concentration of Credit Risk (Details) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2025 USD ($) loan	Dec. 31, 2024 USD ($) loan	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Loans and Investments
Loans and investments, gross	$ 11,489,393	$ 11,304,956
Allowance for credit losses	(240,937)	(238,967)	$ (211,942)	$ (195,664)
Unearned revenue	(32,831)	(31,992)
Loans and investments, net	$ 11,215,625	$ 11,033,997
Percent of Total	100.00%	100.00%
Loan Count \| loan	719	776
Wtd. Avg. Pay Rate (as a percent)	6.94%	6.90%
Wtd. Avg. Remaining Months to Maturity	13 months	13 months 3 days
Wtd. Avg. First Dollar LTV Ratio (as percent)	2.00%
Wtd. Avg. Last Dollar LTV Ratio (as percent)	79.00%
Weighted average remaining months to maturity including extension options	21 months 24 days	22 months 21 days
Exit fee receivable	$ 43,500	$ 46,600
Single-Family Rental
Loans and Investments
Allowance for credit losses	(6,524)	(7,524)	$ (2,737)	$ (1,624)
Bridge loans
Loans and Investments
Loans and investments, gross	$ 11,057,542	$ 10,893,106
Percent of Total	96.00%	96.00%
Loan Count \| loan	627	688
Wtd. Avg. Pay Rate (as a percent)	6.92%	6.89%
Wtd. Avg. Remaining Months to Maturity	11 months 18 days	11 months 18 days
Wtd. Avg. First Dollar LTV Ratio (as percent)	0.00%	0.00%
Wtd. Avg. Last Dollar LTV Ratio (as percent)	79.00%	80.00%
Bridge loans \| Single-Family Rental
Loans and Investments
Number of loans under the loan portfolio \| loan	372	423
Total loan commitment	$ 4,350,000	$ 4,180,000
Mezzanine loans
Loans and Investments
Loans and investments, gross	$ 256,925	$ 255,556
Percent of Total	2.00%	2.00%
Loan Count \| loan	60	58
Wtd. Avg. Pay Rate (as a percent)	7.70%	7.52%
Wtd. Avg. Remaining Months to Maturity	51 months	51 months 24 days
Wtd. Avg. First Dollar LTV Ratio (as percent)	52.00%	51.00%
Wtd. Avg. Last Dollar LTV Ratio (as percent)	81.00%	82.00%
Preferred equity investments
Loans and Investments
Loans and investments, gross	$ 148,845	$ 148,845
Percent of Total	1.00%	1.00%
Loan Count \| loan	27	27
Wtd. Avg. Pay Rate (as a percent)	6.62%	6.42%
Wtd. Avg. Remaining Months to Maturity	50 months 27 days	53 months 27 days
Wtd. Avg. First Dollar LTV Ratio (as percent)	62.00%	62.00%
Wtd. Avg. Last Dollar LTV Ratio (as percent)	80.00%	79.00%
Construction - multifamily
Loans and Investments
Loans and investments, gross	$ 23,005	$ 4,367
Percent of Total	1.00%	1.00%
Loan Count \| loan	4	2
Wtd. Avg. Pay Rate (as a percent)	9.76%	9.97%
Wtd. Avg. Remaining Months to Maturity	22 months 12 days	20 months 24 days
Wtd. Avg. First Dollar LTV Ratio (as percent)	0.00%	0.00%
Wtd. Avg. Last Dollar LTV Ratio (as percent)	36.00%	42.00%
SFR permanent loans
Loans and Investments
Loans and investments, gross	$ 3,076	$ 3,082
Percent of Total	1.00%	1.00%
Loan Count \| loan	1	1
Wtd. Avg. Pay Rate (as a percent)	9.35%	9.36%
Wtd. Avg. Remaining Months to Maturity	7 months 9 days	10 months 9 days
Wtd. Avg. First Dollar LTV Ratio (as percent)	0.00%	0.00%
Wtd. Avg. Last Dollar LTV Ratio (as percent)	40.00%	40.00%
SFR permanent loans \| Single-Family Rental
Loans and Investments
Unpaid principal balance, funded	$ 2,250,000	$ 1,990,000

Exit Fee Receivable

No definition available.

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- Definition

Funded amount, before allowance for credit loss, of financing receivable.

+ References

No definition available.

+ Details

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- Definition

Funded and unfunded amount, before allowance for credit loss, of financing receivable.

+ References

No definition available.

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- Definition

Represents the weighted average First Dollar LTV Ratio that is calculated by comparing the total of the company's senior most dollar and all senior lien positions within the capital stack to the fair value of the underlying collateral to determine the point at which the company will absorb a total loss of its position.

+ References

No definition available.

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- Definition

Represents the weighted average loan to value ratio that is calculated by comparing the total of the carrying value of the company's loan and all senior lien positions within the capital stack to the fair value of the underlying collateral to determine the point at which the company will initially absorb a loss.

+ References

No definition available.

+ Details

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- Definition

Represents a category of loans on real estate expressed as a percentage of total loans on real estate.

+ References

No definition available.

+ Details

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Represents the weighted average remaining maturity period of mortgage loans.

+ References

No definition available.

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- Definition

Mortgage Loans on Real Estate Remaining Maturity Period, Including Extension Options

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No definition available.

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Weighted average interest rate of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

No definition available.

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- Definition

Represents the number of loans related to the real estate property under the loan portfolio.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-X (SX)
-Number 210
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- Definition

Number of mortgage loans within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

+ Details

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Period Type:	instant

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
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- Definition

Amount of unamortized loan commitment, origination, and other costs (fees) and purchase premium (discount) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
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-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481598/310-20-45-1

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- Definition

The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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-SubTopic 80
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