v3.20.4

Financial Derivatives (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Derivative [Line Items] |  |  |
Written credit derivative spread threshold | 20.00% | 20.00% | 20.00%
Upfront points on written credit derivative in excess of threshold |  | 57.0 |
Credit Default Swap, Selling Protection [Member] |  |  |
Derivative [Line Items] |  |  |
Credit risk derivative in excess of threshold, at fair value, net | $ (0.1) | $ (0.1) | $ (1.0)
Total net up-front payments received | $ (2.0) | $ (3.3) | $ (2.0)
Minimum |  |  |
Derivative [Line Items] |  |  |
Spread on written credit derivatives | 4.00% | 1.09% | 4.26%
Upfront points on written credit derivative in excess of threshold | 56.2 |  | 36.9
Maximum |  |  |
Derivative [Line Items] |  |  |
Spread on written credit derivatives | 27.48% | 44.00% | 81.51%
Upfront points on written credit derivative in excess of threshold | 85.2 |  | 75.2

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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 (paid) received on credit derivatives. + References No definition available. + Details
Name: | efc_UpFrontFeesPaidReceivedOnCreditDerivatives
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

X
- 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: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |