Investment in Loans Investment in Loans (Schedule of Residential Mortgage Loans: Performance) (Details) - USD ($) $ in Thousands		Sep. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,940,279	$ 1,417,054
Loans, at fair value	[1],[2]	1,996,529	1,453,480
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		1,602,548	1,150,303
Loans, at fair value		1,656,701	1,187,069
Residential mortgage loans | Performing Financial Instruments [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		18,164	18,120
Loans, at fair value		17,424	16,741
Residential mortgage loans | Non-performing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		34,904	62,009
Loans, at fair value		$ 32,107	$ 58,169

[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.