Variable Interest Entities and Collateralized Loan Obligations - Additional Information (Details)				3 Months Ended
	Feb. 17, 2022 USD ($) CreditFacility	Feb. 16, 2022 USD ($) Loan Participation $ / shares shares	Mar. 31, 2021 USD ($) Loan Participation $ / shares shares	Mar. 31, 2022 USD ($) Loan	Mar. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Collateral (loans), Outstanding principal				$ 1,619,567,000		$ 1,719,735,000
Aggregate principal balance				1,166,996,000		1,167,323,000
Amortization of deferred financing costs				4,521,000	$ 3,818,000
Total loan commitment amount				5,593,350,000		5,411,944,000
Total loans past due				5,115,788,000		4,909,202,000
Interest Expense
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Unamortized deferred transaction costs written off				600,000
Secured Overnight Financing Rate
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Total loan commitment amount				200,000,000
FL3 Mortgage Assets
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Aggregate principal balance				$ 1,100,000,000
Loans held for investment, aggregate unpaid principal balance percentage				20.90%
FL2 Mortgage Assets
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Redemption of investment-grade bonds outstanding	$ 600,000,000.0
FL2 Mortgage Assets | Goldman, Sachs & Co.
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Loans and leases receivable unpaid principal balance	463,800,000
Total loan commitment amount		$ 250,000,000.0
Borrowing	$ 359,100,000
FL5 Mortgage Assets
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Number of secured credit facilities | CreditFacility	17
Loans and leases receivable unpaid principal balance	$ 805,700,000
Variable Interest Entity, Primary Beneficiary
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Number of loans held for investment | Loan				1
Total loans past due				$ 600,000		100,000
FL5 Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Amortization of deferred financing costs				$ 1,100,000
Collateralized Loan Obligation
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Number of mortgage loans originated or acquired | Loan				3
Principal amount of mortgage assets issued				$ 3,400,000,000
Percentage of loans held for investment portfolio collateralized				66.30%
Collateral (loans), Outstanding principal				$ 3,395,746,000		3,164,710,000
Deferred financing costs, including issuance, legal, and accounting related costs				14,489,000		10,297,000
Collateralized Loan Obligation | FL5 Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Notes issued		$ 1,075,000,000.000
Preferred stock, shares issued | shares		76,594
Preferred stock, par value | $ / shares		$ 0.001
Derivative, notional amount		$ 1,000
Deferred financing costs, including issuance, legal, and accounting related costs				6,500,000
Amortization of deferred financing costs				300,000
Unamortized deferred financing costs				6,200,000
Interest expense excluding amortization of deferred financing costs				2,300,000
Collateralized Loan Obligation | FL5 Investment Grade Rated Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Notes issued		907,000,000.0
Collateralized Loan Obligation | FL5 Securities
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Amount used to purchase eligible collateral interests		$ 110,100,000
Number of commercial real estate whole loan | Loan		1
Number of pari passu participations | Participation		26
Number of separate commercial real estate whole loans | Loan		19
Aggregate principal balance				$ 1,100,000,000
Loans held for investment, aggregate unpaid principal balance percentage				21.00%
Cash available to acquire eligible assets				$ 100,000
Collateralized Loan Obligation | FL4 Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Notes issued			$ 1,250,000,000
Preferred stock, shares issued | shares			112,500		112,500
Preferred stock, par value | $ / shares			$ 0.001		$ 0.001
Derivative, notional amount			$ 1,000		$ 1,000
Deferred financing costs, including issuance, legal, and accounting related costs				8,300,000
Amortization of deferred financing costs				700,000
Unamortized deferred financing costs				6,000,000.0		6,700,000
Interest expense excluding amortization of deferred financing costs				4,600,000	0
Collateralized Loan Obligation | FL4 Investment Grade Rated Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Notes issued			1,040,000,000.00
Collateralized Loan Obligation | FL4 Securities
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Amount used to purchase eligible collateral interests			$ 308,900,000
Ramp-up period			6 months
Cash distributed for investment or other corporate uses			$ 104,800,000
Number of commercial real estate whole loan | Loan			1
Number of pari passu participations | Participation			17
Number of separate commercial real estate whole loans | Loan			17
Debt securities							$ 308,900,000
Aggregate principal balance				$ 1,300,000,000
Loans held for investment, aggregate unpaid principal balance percentage				24.40%
Cash available to acquire eligible assets				$ 200,000
Collateralized Loan Obligation | FL3-Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Deferred financing costs, including issuance, legal, and accounting related costs				7,800,000
Amortization of deferred financing costs				700,000	600,000
Unamortized deferred financing costs				2,300,000		$ 3,000,000.0
Interest expense excluding amortization of deferred financing costs				3,800,000	3,800,000
Collateralized Loan Obligation | FL2-Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Deferred financing costs, including issuance, legal, and accounting related costs				8,700,000
Amortization of deferred financing costs					600,000
Interest expense excluding amortization of deferred financing costs				$ 1,400,000	$ 3,100,000