Subsequent Events - Additional Information (Details) $ / shares in Units, $ in Thousands			2 Months Ended		3 Months Ended		12 Months Ended
	Jan. 25, 2019 USD ($) $ / shares	Jul. 03, 2017	Feb. 25, 2019 USD ($) Loan	Feb. 22, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) Rating shares		Dec. 31, 2018 USD ($) Rating shares		Dec. 18, 2018 USD ($) $ / shares	Dec. 31, 2017 USD ($) Rating		Dec. 19, 2017 $ / shares	Dec. 31, 2016 USD ($)
Subsequent Event [Line Items]
Loan commitments					$ 4,947,749		$ 4,947,749			$ 3,727,156
Weighted Average Risk Rating | Rating					2.8		2.8			2.6
Dividend payable date		Jul. 25, 2017					Jul. 03, 2017
Dividends Payable					$ 28,981	[1]	$ 28,981	[1]	$ 29,000	$ 23,068	[1]		$ 18,346
Goldman Sachs & Co. LLC
Subsequent Event [Line Items]
Stock repurchased during period, shares | shares					23,577		1,187,930
Stock repurchased during period, value					$ 400		$ 22,900
Common Stock
Subsequent Event [Line Items]
Dividend amount per share | $ / shares									$ 0.43			$ 0.38
Senior Mortgage Loan
Subsequent Event [Line Items]
Weighted Average Risk Rating | Rating					2.9		2.9
Subsequent Events | Goldman Sachs & Co. LLC
Subsequent Event [Line Items]
Stock repurchased during period, shares | shares				2,324
Weighted average price per share | $ / shares				$ 18.27
Stock repurchased during period, value				$ 40
Plan expiration date				Feb. 28, 2019
Subsequent Events | Common Stock
Subsequent Event [Line Items]
Dividend payable date	Jan. 25, 2019
Dividend record date	Dec. 28, 2018
Dividend amount per share | $ / shares	$ 0.43
Dividends Payable	$ 29,000
Subsequent Events | Senior Mortgage Loan
Subsequent Event [Line Items]
Number of first mortgage loans originated | Loan			10
Loan commitments			$ 629,500
Number of first mortgage loans repayments | Loan			5
Loan repayments related to mortgage loans, loan commitment			$ 262,700
Loan repayments related to mortgage loans, unpaid principal			$ 246,200

[1] The Company’s consolidated Total Assets and Total Liabilities at December 31, 2018 include VIE assets and liabilities of $1.9 billion and $1.5 billion, respectively. These assets were available only to satisfy obligations of the VIE, and creditors of the VIE had recourse only to those assets, and not to TPG RE Finance Trust, Inc. At December 31, 2017, there were no VIE assets or liabilities recorded in the Company’s Total Assets and Total Liabilities. See Note 5 to the Consolidated Financial Statements for details