Borrowings (Details) $ in Thousands				3 Months Ended	9 Months Ended
		Feb. 13, 2019	Aug. 18, 2017 USD ($)	Mar. 31, 2020	Sep. 30, 2020 USD ($) counterparty	Dec. 31, 2019 USD ($) counterparty
Borrowings [Line Items]
Total secured borrowings					$ 2,300,000	$ 3,200,000
Number of Counterparties with Outstanding Reverse Repurchase Agreements | counterparty					24	28
Financial Instruments transferred as collateral for repurchase agreements					$ 1,783,000	$ 2,763,000
Collateral on repurchase agreements, unsettled sales						64,700
Repurchase Agreements amount at risk threshold					10.00%
Other secured borrowings	[1]				$ 142,674	150,334
Other secured borrowings, at fair value	[1]				$ 695,516	$ 594,396
Minimum
Borrowings [Line Items]
Reverse Repurchase Agreements Maturity					30 days
Repurchase agreements, remaining days to maturity				2 days	1 day
Repurchase Agreements Interest Rate					0.22%	0.15%
Maximum
Borrowings [Line Items]
Reverse Repurchase Agreements Maturity					180 days
Repurchase agreements, remaining days to maturity				882 days	608 days
Repurchase Agreements Interest Rate					5.24%	5.20%
Reverse repurchase agreements
Borrowings [Line Items]
Cash collateral posted for securities sold under agreements to repurchase					$ 27,700	$ 31,000
Security Owned and Pledged as Collateral, Fair Value					28	200
Securitized residential mortgage loans
Borrowings [Line Items]
Fair Value of Assets Transfered and Accounted for as Secured Borrowings					761,100	629,100
Secured borrowing recourse facility collateralized by unsecured loan portfolio
Borrowings [Line Items]
Other secured borrowings					$ 10,500	$ 16,000
Debt Instrument, Interest Rate, Effective Rate					2.28%	3.85%
Secured borrowing recourse facility collateralized by unsecured loan portfolio | Unsecured loans
Borrowings [Line Items]
Fair Value of Assets Transfered and Accounted for as Secured Borrowings					$ 13,900	$ 22,300
Non-QM loan securitization
Borrowings [Line Items]
Other secured borrowings						$ 594,400
Debt Instrument, Interest Rate, Effective Rate					2.91%	3.19%
Secured borrowing facility collateralized by unsecured loan portfolio
Borrowings [Line Items]
Other secured borrowings					$ 95,700	$ 102,500
Debt Instrument, Interest Rate, Effective Rate					2.53%	4.01%
Secured borrowing facility collateralized by unsecured loan portfolio | Unsecured loans
Borrowings [Line Items]
Fair Value of Assets Transfered and Accounted for as Secured Borrowings					$ 132,400	$ 144,100
Secured borrowing facility collateralized by ABS backed by consumer loans [Member]
Borrowings [Line Items]
Other secured borrowings					$ 30,200	$ 31,800
Debt Instrument, Interest Rate, Effective Rate					5.20%	5.23%
Fair Value of Assets Transfered and Accounted for as Secured Borrowings					$ 46,900	$ 47,900
Commercial mortgage loans
Borrowings [Line Items]
Other secured borrowings					6,300
Fair Value of Assets Transfered and Accounted for as Secured Borrowings					$ 16,900
Senior Notes
Borrowings [Line Items]
Debt Instrument, Interest Rate, Effective Rate					5.80%
Debt Instrument, Face Amount			$ 86,000
Proceeds from Debt, Net of Issuance Costs			$ 84,700
Debt Instrument, Interest Rate, Stated Percentage		5.50%	5.25%
Redemption percentage		100.00%
Debt Instrument, Maturity Date			Sep. 01, 2022

[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.