Counterparty Risk (Cash and Cash Equivalents) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	[1]	Dec. 31, 2019	[1]	Dec. 31, 2018
Concentration Risk [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 111,647		$ 72,302		$ 44,656
Bank of New York Mellon Corporation [Member]
Concentration Risk [Line Items]
Concentration risk percentage, cash and cash equivalents					64.00%
Deutsche Bank Securities [Member]
Concentration Risk [Line Items]
Concentration risk percentage, cash and cash equivalents					5.00%
Bank of America Securities [Member]
Concentration Risk [Line Items]
Concentration risk percentage, cash and cash equivalents					2.00%
Morgan Stanley Institutional Liquidity Fund - Government Portfolio [Member]
Concentration Risk [Line Items]
Concentration risk percentage, cash and cash equivalents					10.00%
BlackRock Liquidity Funds FedFund Portfolio, Institutional Class Shares [Member]
Concentration Risk [Line Items]
Concentration risk percentage, cash and cash equivalents					9.00%
Goldman Sachs Financial Square Funds - Government Fund [Member]
Concentration Risk [Line Items]
Concentration risk percentage, cash and cash equivalents					9.00%
US Bank N.A. [Member]
Concentration Risk [Line Items]
Concentration risk percentage, cash and cash equivalents					1.00%

[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.