Investment in Loans Investment in Loans (Schedule of Residential Mortgage Loans: Performance) (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$ 1,387,733
Loans, at fair value	1,412,426	[1]
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	911,705
Loans, at fair value	932,203
Residential mortgage loans | Performing Financial Instruments [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	27,663
Loans, at fair value	25,323
Residential mortgage loans | Non-performing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	17,757
Loans, at fair value	$ 15,580

[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.