Investment in Loans (Schedule of 90 Days or More Past Due) (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		$ 1,414,410	$ 1,387,733
Loans, at fair value	[1]	1,442,612	1,412,426
Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		252,305	277,870
Loans, at fair value		252,231	274,759
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		1,004,980	911,705
Loans, at fair value		1,030,709	932,203
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		150,062	179,743
Loans, at fair value		152,609	186,954
Non-accrual status [Member] | Commercial mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at fair value		23,800	10,700
Non-accrual status [Member] | Commercial mortgage loans | 90 Days or More Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		23,750	28,936
Loans, at fair value		23,671	26,545
Non-accrual status [Member] | Residential mortgage loans | 90 Days or More Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		67,121	22,092
Loans, at fair value		64,414	19,401
Non-accrual status [Member] | Consumer loans | 90 Days or More Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance		1,284	5,633
Loans, at fair value		$ 1,131	$ 5,225

[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.