v3.8.0.1

Financial Derivatives Financial Derivatives (Schedule of Derivative Activity) (Details) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2017 | Dec. 31, 2016
Interest Rate Swaps [Member] |  |
Derivative [Line Items] |  |
Average Monthly Notional Amount | $ 1,270,482 | $ 1,731,368
Credit Default Swap [Member] |  |
Derivative [Line Items] |  |
Average Monthly Notional Amount | 489,515 | 1,586,923
Total Return Swaps [Member] |  |
Derivative [Line Items] |  |
Average Monthly Notional Amount | 22,536 | 113,628
Futures [Member] |  |
Derivative [Line Items] |  |
Average Monthly Notional Amount | 57,240 | 371,900
Options [Member] |  |
Derivative [Line Items] |  |
Average Monthly Notional Amount | 88,699 | 357,260
Forwards [Member] |  |
Derivative [Line Items] |  |
Average Monthly Notional Amount | 74,623 | 80,513
Warrant [Member] |  |
Derivative [Line Items] |  |
Average Monthly Notional Amount | 492 | 1,640
Mortgage Loan Purchase Commitments [Member] |  |
Derivative [Line Items] |  |
Average Monthly Notional Amount | $ 2,060 | $ 6,143

X
- Definition Average notional for the period using absolute value of month end notional amounts. + References No definition available. + Details
Name: | efc_FinancialDerivativeAverageMonthlyNotional
Namespace Prefix: | efc_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- 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

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CreditDefaultSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_TotalReturnSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_FutureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=efc_OptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ForwardContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_WarrantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_LoanPurchaseCommitmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |