Investment in Loans (Schedule of Residential Mortgage Loans) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,417,054	$ 1,387,733
Unamortized Premium (Discount)		(196,118)	(150,821)
Amortized Cost				$ 2,970,306
Fair Value	[1],[2]	$ 1,453,480	$ 1,412,426
Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		3.92%	4.23%
Weighted Average Yield		4.77%	4.01%
Weighted average life		4 years 5 months 26 days	5 years 10 months 24 days
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,150,303	$ 911,705
Fair Value		1,187,069	932,203
Residential mortgage loans | Non-performing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		62,009	17,757
Fair Value		58,169	15,580
Consolidated securitization trusts [Member] | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gains		24,800	11,300
Losses		100	100
Loans held-for-investment [Member] | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		1,150,303	911,705
Unamortized Premium (Discount)		14,263	9,354
Amortized Cost		1,164,566	921,059
Gains		27,892	13,082
Losses		(5,389)	(1,938)
Fair Value		$ 1,187,069	$ 932,203
Loans held-for-investment [Member] | Residential mortgage loans | Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		6.19%	6.44%
Weighted Average Yield		5.60%	5.79%
Weighted average life		1 year 10 months 24 days	1 year 10 months 24 days
Non-QM loan securitization | Residential mortgage loans | Consolidated Entities [Member] | Securitized loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value		$ 801,343	$ 628,415

[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.

[2] Includes assets pledged as collateral to counterparties. See Note 11 for additional details on the Company's borrowings and related collateral.