v3.8.0.1

Financial Derivatives (Narrative) (Details) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2017 | Dec. 31, 2016
Derivative [Line Items] |  |
Written credit derivative spread threshold | 20.00% | 20.00%
Credit Default Swap, Selling Protection [Member] |  |
Derivative [Line Items] |  |
Credit Risk Derivative in Excess of Threshold, at Fair Value, Net | $ (1.3) | $ (2.5)
Total net up-front payments received | $ (3.0) | $ (3.3)
Minimum [Member] |  |
Derivative [Line Items] |  |
Low Range Of Spread On Written Credit Derivatives | 0.056% | 0.685%
Upfront points on written credit derivative in excess of threshold | 51.5 | 45.0
Maximum [Member] |  |
Derivative [Line Items] |  |
Low Range Of Spread On Written Credit Derivatives | 12.958% | 6.366%
Upfront points on written credit derivative in excess of threshold | 93.5 | 72.6

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- Definition Net fair value of credit risk derivatives in excess of implied credit spread threshold. + References No definition available. + Details
Name: | efc_CreditRiskDerivativeinExcessofThresholdatFairValueNet
Namespace Prefix: | efc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Implied spread on written credit derivative + References No definition available. + Details
Name: | efc_Impliedspreadonwrittencreditderivative
Namespace Prefix: | efc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- Definition Total net upfront fees received on credit derivatives. + References No definition available. + Details
Name: | efc_UpFrontFeesReceivedOnCreditDerivatives
Namespace Prefix: | efc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Definition Estimated upfront points on written credit derivative contract at period end for those contracts where the current spread is in excess of a predetermined threshold. + References No definition available. + Details
Name: | efc_Upfrontpointsonwrittencreditderivative
Namespace Prefix: | efc_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

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- Definition Implied credit spread threshold whereby the contracts trade based on points paid up front. + References No definition available. + Details
Name: | efc_Writtencreditderivativespreadthreshold
Namespace Prefix: | efc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_CreditDerivativesByContractTypeAxis=us-gaap_CreditDefaultSwapSellingProtectionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |