Variable Interest Entities and Collateralized Loan Obligations - Schedule of Borrowings and Corresponding Collateral (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2026 USD ($) loan	Sep. 30, 2025 USD ($)	Sep. 30, 2026 USD ($) loan	Sep. 30, 2025 USD ($)	Dec. 31, 2025 USD ($) loan
Debt Instrument [Line Items]
Count (in loans) \| loan	59		59		50
Other real estate owned investments held by sub real estate investment trust	$ 86,700		$ 86,700		$ 84,700
Interest expense	55,655	$ 48,818	154,504	$ 137,485
Amortization of debt issuance costs and discounts			6,598	4,605
Collateralized loan obligations
Debt Instrument [Line Items]
Interest expense	27,700	38,700	96,000	106,200
Amortization of debt issuance costs and discounts	1,200	$ 700	3,500	$ 2,000
Collateralized loan obligations \| Collateral Assets
Debt Instrument [Line Items]
Outstanding principal balance	2,200,000		2,200,000		3,043,784
Carrying value	$ 2,176,395		$ 2,176,395		$ 2,996,305
Collateralized loan obligations \| Collateral loan investments
Debt Instrument [Line Items]
Count (in loans) \| loan	40		40		59
Wtd. avg. spread	3.07%		3.07%		3.25%
Wtd. avg. maturity			3 years 2 months 12 days		3 years
Collateralized loan obligations \| Debt
Debt Instrument [Line Items]
Count (in loans) \| loan	2		2		3
Outstanding principal balance	$ 1,919,500		$ 1,919,500		$ 2,595,316
Carrying value	$ 1,907,145		$ 1,907,145		$ 2,579,920
Wtd. avg. spread	1.75%		1.75%		1.85%
Wtd. avg. maturity			16 years 3 months 18 days		16 years
Collateralized loan obligations \| TRTX 2022-FL5 \| Collateral Assets
Debt Instrument [Line Items]
Outstanding principal balance					$ 843,784
Carrying value					$ 822,488
Collateralized loan obligations \| TRTX 2022-FL5 \| Collateral loan investments
Debt Instrument [Line Items]
Count (in loans) \| loan					19
Wtd. avg. spread					3.52%
Wtd. avg. maturity					1 year 6 months
Loans held for investment, aggregate unpaid principal balance percentage					20.50%
Collateralized loan obligations \| TRTX 2022-FL5 \| Debt
Debt Instrument [Line Items]
Count (in loans) \| loan					1
Outstanding principal balance					$ 675,816
Carrying value					$ 675,816
Wtd. avg. spread					2.14%
Wtd. avg. maturity					13 years 1 month 6 days
Collateralized loan obligations \| TRTX 2025-FL6 \| Collateral Assets
Debt Instrument [Line Items]
Outstanding principal balance	$ 1,100,000		$ 1,100,000		$ 1,100,000
Carrying value	$ 1,087,004		$ 1,087,004		$ 1,086,326
Collateralized loan obligations \| TRTX 2025-FL6 \| Collateral loan investments
Debt Instrument [Line Items]
Count (in loans) \| loan	19		19		19
Wtd. avg. spread	3.05%		3.05%		3.15%
Wtd. avg. maturity			3 years 3 months 18 days		3 years 3 months 18 days
Loans held for investment, aggregate unpaid principal balance percentage	22.30%		22.30%		26.60%
Collateralized loan obligations \| TRTX 2025-FL6 \| Debt
Debt Instrument [Line Items]
Count (in loans) \| loan	1		1		1
Outstanding principal balance	$ 962,500		$ 962,500		$ 962,500
Carrying value	$ 956,171		$ 956,171		$ 954,133
Wtd. avg. spread	1.83%		1.83%		1.83%
Wtd. avg. maturity			15 years 10 months 24 days		16 years 8 months 12 days
Collateralized loan obligations \| TRTX 2025-FL7 \| Collateral Assets
Debt Instrument [Line Items]
Outstanding principal balance	$ 1,100,000		$ 1,100,000		$ 1,100,000
Carrying value	$ 1,089,391		$ 1,089,391		$ 1,087,491
Collateralized loan obligations \| TRTX 2025-FL7 \| Collateral loan investments
Debt Instrument [Line Items]
Count (in loans) \| loan	21		21		21
Wtd. avg. spread	3.09%		3.09%		3.14%
Wtd. avg. maturity			3 years 2 months 12 days		3 years 10 months 24 days
Loans held for investment, aggregate unpaid principal balance percentage	22.10%		22.10%		26.70%
Collateralized loan obligations \| TRTX 2025-FL7 \| Debt
Debt Instrument [Line Items]
Count (in loans) \| loan	1		1		1
Outstanding principal balance	$ 957,000		$ 957,000		$ 957,000
Carrying value	$ 950,974		$ 950,974		$ 949,971
Wtd. avg. spread	1.67%		1.67%		1.67%
Wtd. avg. maturity			16 years 8 months 12 days		17 years 4 months 24 days