Investment in Loans (Narrative) (Details) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2021 USD ($) loan	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value	[1],[2]	$ 1,582,516		$ 1,453,480
Unpaid Principal Balance		1,536,714		1,417,054
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		1,280,637		1,187,069
Mortgage Loans in Process of Foreclosure, Amount		16,400		14,900
Unpaid Principal Balance		1,236,923		1,150,303
Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		235,948		213,031
Losses		(455)		(454)
Financing Receivable, Allowance for Credit Loss		400		400
Mortgage Loans in Process of Foreclosure, Amount				10,500
Unpaid Principal Balance		235,077		$ 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		52,705		$ 47,525
Losses		(1,389)		(1,887)
Unpaid Principal Balance		51,488		48,180
Delinquent loans, charged off		3,600	$ 4,900
Financing Receivable, Allowance for Credit Loss		1,300		2,900
Fair value of charged-off loans		500		600
Non-performing | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		49,586		58,169
Unpaid Principal Balance		53,289		62,009
Non-performing | Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		$ 34,300		$ 31,500
Number of loans | loan		4		3
Unpaid Principal Balance		$ 34,400		$ 31,800
Loans held-for-investment [Member] | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		1,280,637		1,187,069
Losses		(4,887)		(5,389)
Financing Receivable, Allowance for Credit Loss		1,600		2,200
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date		200		200
Unpaid Principal Balance		1,236,923		$ 1,150,303
Realized Losses, Write offs on loans		(33)
Loans held-for-investment [Member] | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Realized Losses, Write offs on loans		$ (1,300)

[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.