Counterparty Risk (% Of Total Deposits With Dealers Held As Collateral) (Details)	Dec. 31, 2012
Citigroup [Member]
Financial Highlights [Line Items]
% of Total Deposits with Dealers Held as Collateral	41.00%
Bank Of America [Member]
Financial Highlights [Line Items]
% of Total Deposits with Dealers Held as Collateral	30.00%

Percentage of total collateral (other than on reverse repurchase agreements) held by a specific counterparty above a specified concentration risk threshold.

No definition available.

Name:	efc_PercentageOfTotalDepositsWithDealersHeldAsCollateral
Namespace Prefix:	efc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant