Stockholders' Equity - Additional Information (Details) - USD ($)						3 Months Ended
	Mar. 19, 2019	Mar. 07, 2019	Apr. 25, 2018	Mar. 19, 2018	Feb. 28, 2018	Mar. 31, 2019		Mar. 31, 2018	Dec. 31, 2018		Aug. 21, 2017
Class Of Stock [Line Items]
Common stock, par value						$ 0.001			$ 0.001
Proceeds from issuance of common stock						$ 119,100,000
Proceeds from issuance of preferred stock						125,000
Redemption of preferred stock								$ (125,000)
Unpaid dividends	$ 31,600,000					31,598,000	[1]	25,307,000	$ 28,981,000	[1]
Dividends			$ 25,300,000			31,600,000		25,300,000
Other comprehensive (loss) income						$ 106,000		(214,000)
Series A Preferred Stock
Class Of Stock [Line Items]
Number of common shares issued						125
Dividend rate						12.50%
Preferred stock, liquidation preference per annum						$ 1,000
Proceeds from issuance of preferred stock						$ 100,000
Redemption of preferred stock					$ 100,000
Class A Common Stock
Class Of Stock [Line Items]
Common stock, par value						$ 0.001			$ 0.001
Dividend declared per share	$ 0.43			$ 0.42
Dividends						$ 31,600,000		$ 25,300,000
Common Stock And Class A Common Stock
Class Of Stock [Line Items]
Dividend payable date	Apr. 25, 2019		Apr. 25, 2018
Dividend record date	Mar. 29, 2019		Mar. 29, 2018
Dividend payable declared date				Mar. 19, 2018
Goldman Sachs & Co. LLC
Class Of Stock [Line Items]
Number of common shares issued											35,000,000
Description on purchase plan agreement						as our agent, to buy in the open market up to $35.0 million in shares of our common stock in the aggregate during the period beginning on or about August 21, 2017 and ending 12 months thereafter or, if sooner, the date on which all the capital committed has been exhausted. On August 1, 2018, the Company’s Board of Directors authorized the Company to extend the repurchase period for the remaining capital committed to the 10b5-1 Purchase Plan. No other changes to the terms of the 10b5-1 Purchase Plan were authorized. Under the amended 10b5-1 Purchase Plan, the repurchase period was extended to February 28, 2019 or, if sooner, the date on which all the capital committed to the 10b5-1 Purchase Plan has been exhausted.
Stock repurchased during period, shares						2,324
Average price of repurchased shares						$ 18.27
Stock repurchased during period, value						$ 40,000
Purchase plan, expiration date						Feb. 28, 2019
Common Stock
Class Of Stock [Line Items]
Number of common shares issued	6,000,000					6,000,000
Shares issued, price per share	$ 19.80
Proceeds from issuance of common stock	$ 118,800,000
Offering costs reimbursed by manager	$ 300,000
Dividend declared per share	$ 0.43			$ 0.42
Equity Distribution Agreement
Class Of Stock [Line Items]
Common stock, par value		$ 0.001
Equity Distribution Agreement | Common Stock
Class Of Stock [Line Items]
Number of common shares issued						0
Equity Distribution Agreement | Common Stock | Maximum
Class Of Stock [Line Items]
Aggregate gross sales price of common stock		$ 125,000,000
Percentage of commission to each sales agent, on gross sales price of shares sold		1.75%

[1] The Company’s consolidated Total Assets and Total Liabilities at March 31, 2019 include assets and liabilities of variable interest entities (“VIEs”) of $1.7 billion and $1.3 billion, respectively. The Company’s consolidated Total Assets and Total Liabilities at December 31, 2018 include assets and liabilities of VIEs of $1.9 billion and $1.5 billion, respectively. These assets can be used only to satisfy obligations of the VIEs, and creditors of the VIEs have recourse only to these assets, and not to TPG RE Finance Trust, Inc. See Note 5 to the Consolidated Financial Statements for details