Investment in Loans (Narrative) (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,414,410		$ 1,414,410		$ 1,387,733
Loans, at fair value	[1]	1,442,612		1,442,612		1,412,426
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impairment Losses, Recognized in Earnings			$ 300		$ 700
Mortgage Loans in Process of Foreclosure, Amount		11,100		11,100		10,900
Unpaid Principal Balance		1,004,980		1,004,980		911,705
Loans, at fair value		1,030,709		1,030,709		932,203
Residential mortgage loans | Non-performing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		64,710		64,710		17,757
Loans, at fair value		62,343		62,343		15,580
Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Losses		(487)		(487)		(62)
Financing Receivable, Allowance for Credit Loss		400		400
Mortgage Loans in Process of Foreclosure, Amount						$ 16,000
Number of mortgage loans in process of foreclosure						2
Unpaid Principal Balance		252,305		252,305		$ 277,870
Loans, at fair value		$ 252,231		$ 252,231		$ 274,759
Commercial mortgage loans | Non-performing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan		2		2		3
Unpaid Principal Balance		$ 23,800		$ 23,800		$ 28,900
Loans, at fair value		23,700		23,700		26,500
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Losses		(6,230)		(6,230)		(377)
Financing Receivable, Allowance for Credit Loss				4,700
Delinquent loans, charged off		3,900	4,900	13,900	13,900
Fair value of charged-off loans		600		600		600
Impairment Losses, Recognized in Earnings			$ 1,100		$ 4,600
Unpaid Principal Balance		150,062		150,062		179,743
Loans, at fair value		152,609		152,609		186,954
Corporate loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		7,063		7,063		18,415
Loans, at fair value		7,063		7,063		18,510
Loans held-for-investment [Member] | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Losses		(4,355)		(4,355)		(1,938)
Financing Receivable, Allowance for Credit Loss		2,600		2,600
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date				400
Realized Losses, Write offs on loans		51		(500)
Unpaid Principal Balance		996,429		996,429		911,705
Loans, at fair value		1,022,254		1,022,254		$ 932,203
Loans held-for-investment [Member] | Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Realized Losses, Write offs on loans		$ 100		$ 100

[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.