Investment in Loans (Schedule of Commercial Mortgage Loans) (Details) (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,402,045	$ 1,387,733
Unamortized Premium (Discount)		(189,940)	(150,821)
Loans, at fair value	[1]	$ 1,416,851	$ 1,412,426
Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		4.05%	4.23%
Weighted Average Yield		5.10%	4.01%
Weighted average life		4 years 5 months 19 days	5 years 10 months 24 days
Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 295,621	$ 277,870
Unamortized Premium (Discount)		(182)	(3,302)
Amortized Cost		295,439	274,568
Gains		808	253
Losses		(751)	(62)
Loans, at fair value		$ 295,496	$ 274,759
Number of mortgage loans in process of foreclosure		1	2
Mortgage Loans in Process of Foreclosure, Amount		$ 10,700	$ 16,000
Commercial mortgage loans | Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		8.28%	7.65%
Weighted Average Yield		8.25%	8.58%
Weighted average life		11 months 8 days	1 year 25 days
Non-accrual status [Member] | Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		$ 23,900	$ 10,700

[1] Ellington Financial Inc.'s Condensed Consolidated Balance Sheet includes assets and liabilities of variable interest entities it has consolidated. See Note 9 for additional details on Ellington Financial Inc.'s consolidated variable interest entities.