Borrowings (Details) $ in Thousands			12 Months Ended
	Feb. 13, 2019 USD ($)	Aug. 18, 2017 USD ($)	Dec. 31, 2019 USD ($) counterparty		Dec. 31, 2018 USD ($) counterparty
Borrowings [Line Items]
Total secured borrowings			$ 3,200,000		$ 1,911,000
Concentration Risk, Reverse Repurchase Agreements					21.00%
Number of Counterparties With Concentration Risk, Reverse Repurchase Agreements | counterparty					1
Number of Counterparties with Outstanding Reverse Repurchase Agreements | counterparty			28		23
Financial Instruments transferred as collateral for repurchase agreements			$ 2,763,000		$ 1,790,000
Financial Instruments transferred as collateral for repurchase agreements, Unsettled			$ 64,700		$ 86,700
Repurchase Agreements amount at risk threshold			10.00%		10.00%
Other secured borrowings			$ 150,334	[1]	$ 114,100
Minimum
Borrowings [Line Items]
Reverse Repurchase Agreements Maturity			30 days		30 days
Repurchase agreements, remaining days to maturity			2 days		2 days
Repurchase Agreements Interest Rate			0.15%		0.23%
Maximum
Borrowings [Line Items]
Reverse Repurchase Agreements Maturity			180 days		180 days
Repurchase agreements, remaining days to maturity			882 days		871 days
Repurchase Agreements Interest Rate			5.20%		6.07%
Reverse repurchase agreements
Borrowings [Line Items]
Cash collateral posted for securities sold under agreements to repurchase			$ 31,000		$ 17,000
Security Owned and Pledged as Collateral, Fair Value			200		200
Securitized residential mortgage loans
Borrowings [Line Items]
Fair Value of Assets Transfered and Accounted for as Secured Borrowings			629,100		314,200
Secured borrowing recourse facility collateralized by unsecured loan portfolio
Borrowings [Line Items]
Other secured borrowings			$ 16,000		$ 13,200
Debt Instrument, Interest Rate, Effective Rate			3.85%
Debt Instrument, Interest Rate, Stated Percentage					4.72%
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			$ 22,300		$ 20,300
Non-QM loan securitization
Borrowings [Line Items]
Other secured borrowings			$ 594,400		$ 297,900
Debt Instrument, Interest Rate, Effective Rate			3.19%
Debt Instrument, Interest Rate, Stated Percentage					3.72%
Secured borrowing facility collateralized by unsecured loan portfolio
Borrowings [Line Items]
Other secured borrowings			$ 102,500		$ 101,000
Debt Instrument, Interest Rate, Effective Rate			4.01%
Debt Instrument, Interest Rate, Stated Percentage					4.68%
Secured borrowing facility collateralized by unsecured loan portfolio | Unsecured loans
Borrowings [Line Items]
Fair Value of Assets Transfered and Accounted for as Secured Borrowings			$ 144,100		$ 149,000
Secured borrowing facility collateralized by ABS backed by consumer loans [Member]
Borrowings [Line Items]
Other secured borrowings			$ 31,800
Debt Instrument, Interest Rate, Effective Rate			5.23%
Fair Value of Assets Transfered and Accounted for as Secured Borrowings			$ 47,900
Senior Notes
Borrowings [Line Items]
Debt Instrument, Interest Rate, Effective Rate			5.80%
Debt Instrument, Face Amount	$ 86,000	$ 86,000
Proceeds from Debt, Net of Issuance Costs		$ 84,700
Debt Instrument, Interest Rate, Stated Percentage	5.50%	5.25%			5.55%
Redemption percentage	100.00%	100.00%
Debt Instrument, Maturity Date		Sep. 01, 2022

[1] Ellington Financial Inc.'s 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.