Investment in Loans (Schedule of Residential Mortgage Loans) (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,230,004
Unamortized Premium (Discount)		(106,592)
Amortized Cost			$ 2,970,306
Fair Value	[1]	$ 1,225,843
Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		4.25%
Weighted Average Yield		4.24%
Weighted average life		5 years 128 days
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 780,920
Fair Value		797,728
Loans held-for-investment [Member] | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		780,920
Unamortized Premium (Discount)		6,748
Amortized Cost		787,668
Gains		11,309
Losses		(1,249)
Fair Value		$ 797,728
Loans held-for-investment [Member] | Residential mortgage loans | Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		6.45%
Weighted Average Yield		5.46%
Weighted average life		1 year 172 days
Non-QM loan securitization | Residential mortgage loans | Consolidated Entities [Member] | Securitized loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value		$ 466,297

[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.