Investment in Loans (Schedule of Residential Mortgage Loans) (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,441,017	$ 1,387,733
Unamortized Premium (Discount)		(174,092)	(150,821)
Fair Value	[1]	$ 1,443,589	$ 1,412,426
Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		4.13%	4.23%
Weighted Average Yield		4.96%	4.01%
Weighted average life		4 years 5 months 12 days	5 years 10 months 24 days
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 940,480	$ 911,705
Fair Value		939,372	932,203
Consolidated securitization trusts [Member] | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gains		9,000
Losses		700
Loans held-for-investment [Member] | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		940,480	911,705
Unamortized Premium (Discount)		12,314	9,354
Amortized Cost		952,794	921,059
Gains		9,969	13,082
Losses		(23,391)	(1,938)
Fair Value		$ 939,372	$ 932,203
Loans held-for-investment [Member] | Residential mortgage loans | Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		6.33%	6.44%
Weighted Average Yield		5.86%	5.79%
Weighted average life		3 years 5 months 23 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		$ 581,181	$ 628,415

[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.