Variable Interest Entities and Collateralized Loan Obligations - Additional Information (Details) - USD ($)		3 Months Ended
	Feb. 14, 2018	Mar. 31, 2019	Dec. 31, 2018	Nov. 29, 2018
Class A Senior Secured Note
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Replenishment feature utilization amount		$ 247,400,000
Replenishment feature utilization percentage		50.30%
FL2-Securities
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Liquidation preference notional amount				$ 1,000
FL1-Securities
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Liquidation preference notional amount	$ 1,000
TPG Real Estate Finance 2018-FL2 Issuer, Ltd. and TPG RE Finance Trust 2018-FL2 Co-Issuer, LLC
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Preferred shares par value per share				$ 0.001
TPG Real Estate Finance 2018-FL2 Issuer, Ltd. and TPG RE Finance Trust 2018-FL2 Co-Issuer, LLC | FL2-Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Principal amount of notes issued				$ 872,600,000
FL2-Co-Issuer
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Principal amount of notes issued				795,100,000
FL2-Retention Holder | FL2-Securities
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Variable interest entity retained ownership amount				$ 205,000,000
F L2 Mortgage Assets
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Principal amount of notes issued		$ 993,600,000
Loans held for investment, aggregate unpaid principal balance percentage		21.10%
TPG Real Estate Finance 2018-FL1 Issuer, Ltd. and TPG RE Finance Trust 2018-FL1 Co-Issuer, LLC
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Preferred shares par value per share	$ 0.001
TPG Real Estate Finance 2018-FL1 Issuer, Ltd. and TPG RE Finance Trust 2018-FL1 Co-Issuer, LLC | FL1-Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Principal amount of notes issued	$ 820,500,000
FL1-Co-Issuer
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Principal amount of notes issued	745,900,000
FL1-Retention Holder | FL1-Securities
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Variable interest entity retained ownership amount	186,500,000
FL1-Mortgage Assets
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Principal amount of notes issued		$ 685,000,000
Loans held for investment, aggregate unpaid principal balance percentage		14.50%
Collateralized Loan Obligation
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Principal amount of notes issued		$ 1,261,554,000	$ 1,527,237,000
Net cash proceeds utilizing replenishment feature		6,400,000
Companion participation interests related to replenishment		31,800,000
Repayment of existing borrowings including accrued interest		25,400,000
Unamortized issuance costs		10,161,000	$ 12,447,000
Collateralized Loan Obligation | FL2-Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Payments to acquire variable interest entity (principal amount)		19,700,000
Debt issuance costs, gross		8,700,000
Unamortized issuance costs		7,900,000
Interest expense excluding amortization of deferred financing costs		7,700,000
Collateralized Loan Obligation | FL1-Notes
Variable Interest Entities And Collateralized Loan Obligation [Line Items]
Debt issuance costs, gross		9,800,000
Unamortized issuance costs		2,300,000
Interest expense excluding amortization of deferred financing costs		5,400,000
Payments to acquire variable interest entity as an investment (principal amount)	$ 12,400,000	$ 9,900,000