Investment in Loans Investment in Loans (Schedule of Corporate 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
Loans, at fair value	[1],[2]	1,996,529	1,453,480
Corporate loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		16,828	5,855
Loans, at fair value		$ 16,561	$ 5,855
Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		3.63%	3.92%
Weighted average life		5 years 11 months 4 days	4 years 5 months 26 days
Weighted Average | Corporate loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		17.68%	20.00%
Weighted average life		2 years 10 months 28 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.