Investment in Loans (Narrative) (Details) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2021 USD ($) loan	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) loan	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value	[1],[2]	$ 1,742,701		$ 1,742,701		$ 1,453,480
Unpaid Principal Balance		1,689,648		1,689,648		1,417,054
Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		228,450		228,450		213,031
Losses		(328)		(328)		(454)
Financing Receivable, Allowance for Credit Loss		400		400		400
Mortgage Loans in Process of Foreclosure, Amount						10,500
Unpaid Principal Balance		228,318		228,318		$ 212,716
Number of mortgage loans in process of foreclosure						1
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		52,016		52,016		$ 47,525
Losses		(1,251)		(1,251)		(1,887)
Unpaid Principal Balance		50,312		50,312		48,180
Delinquent loans, charged off		500	$ 5,100	2,400	$ 10,000
Financing Receivable, Allowance for Credit Loss				1,200		2,900
Fair value of charged-off loans		400		400		600
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		1,445,651		1,445,651		1,187,069
Mortgage Loans in Process of Foreclosure, Amount		16,000		16,000		14,900
Unpaid Principal Balance		1,394,434		1,394,434		1,150,303
Non-performing | Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		$ 36,400		$ 36,400		$ 31,500
Number of loans | loan		6		6		3
Unpaid Principal Balance		$ 36,300		$ 36,300		$ 31,800
Non-performing | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		39,421		39,421		58,169
Unpaid Principal Balance		42,236		42,236		62,009
Loans held-for-investment [Member] | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Realized Losses, Write offs on loans				(1,300)
Loans held-for-investment [Member] | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		1,445,651		1,445,651		1,187,069
Losses		(4,590)		(4,590)		(5,389)
Financing Receivable, Allowance for Credit Loss		2,100		2,100		2,200
Unpaid Principal Balance		$ 1,394,434		1,394,434		1,150,303
Realized Losses, Write offs on loans			$ (500)	(33)	$ (500)
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date				$ 100		$ 200

[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.

[2] Includes assets pledged as collateral to counterparties. See Note 11 for additional details on the Company's borrowings and related collateral.