Investment in Loans (Schedule of Consumer Loans) (Details) - USD ($) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,940,279	$ 1,417,054
Unamortized Premium (Discount)		(143,084)	(196,118)
Loans, at fair value	[1],[2]	$ 1,996,529	$ 1,453,480
Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted average life		5 years 11 months 4 days	4 years 5 months 26 days
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair value of charged-off loans		$ 300	$ 600
Unpaid Principal Balance		53,515	48,180
Unamortized Premium (Discount)		2,405	72
Investments, at fair value, Cost		55,920	48,252
Gains		910	1,160
Losses		(1,154)	(1,887)
Loans, at fair value		$ 55,676	$ 47,525
Consumer loans | Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted average life		11 months 15 days	1 year 14 days
Delinquency (Days)		3 days	7 days

[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.