Investment in Loans (Schedule of Commercial Mortgage Loans) (Details) (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,100,062
Unamortized Premium (Discount)		(127,647)
Amortized Cost			$ 2,970,306
Loans, at fair value	[1]	$ 1,091,523
Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		4.21%
Weighted Average Yield		4.47%
Weighted average life		6 years 18 days
Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 285,169
Unamortized Premium (Discount)		(25,057)
Amortized Cost		260,112
Gains		479
Losses		(557)
Loans, at fair value		$ 260,034
Commercial mortgage loans | Weighted Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted Average Coupon		8.72%
Weighted Average Yield		9.98%
Weighted average life		1 year 18 days
Non-accrual status [Member] | Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		$ 25,700

[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.