Investment in Loans Investment in Loans (Schedule of Corporate Loans) (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,536,714	$ 1,417,054
Loans, at fair value	[1],[2]	1,582,516	1,453,480
Corporate loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		13,226	5,855
Loans, at fair value		$ 13,226	$ 5,855
Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		3.68%	3.92%
Weighted average life		5 years 4 months 17 days	4 years 5 months 26 days
Weighted Average | Corporate loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		21.02%	20.00%
Weighted average life		3 years 1 month 17 days	1 year 9 months

[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.