XML 128 R108.htm IDEA: XBRL DOCUMENT
v3.20.4

Fair Value of Financial Instruments (Fair Value Methodology) (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Residential whole loans, at fair value | $ 1,216,637 | $ 1,381,113
Purchases excluded | 265 | 470
Discounted cash flow |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Residential whole loans, at fair value | 789,576 | 829,842
Liquidation model |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Residential whole loans, at fair value | 427,061 | 551,271
Simple average amount | $ 380 | $ 365
Residential whole loans, at fair value | Level 3 | Liquidation model | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Annual change in home prices | 0.00% | 2.40%
Liquidation timeline (in years) | 9 months 18 days | 1 month 6 days
Current value of underlying properties | $ 12 | $ 10
Residential whole loans, at fair value | Level 3 | Liquidation model | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Annual change in home prices | 6.50% | 8.00%
Liquidation timeline (in years) | 4 years 9 months 18 days | 4 years 6 months
Current value of underlying properties | $ 4,500 | $ 4,500
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.033 | 0.038
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.080 | 0.080
Discount rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.039 | 0.042
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.067 | 0.062
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.500 | 0.500
Discount rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.081 | 0.080
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.000 | 0.007
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.099 | 0.180
Prepayment rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.048 | 0.045
Prepayment rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Annual change in home prices | 3.60% | 3.70%
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.000 | 0.000
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.189 | 0.230
Default rate | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.038 | 0.04
Default rate | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Liquidation timeline (in years) | 1 year 9 months 18 days | 1 year 9 months 18 days
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.000 | 0.000
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 1.000 | 1.000
Loss severity | Residential whole loans, at fair value | Level 3 | Discounted cash flow | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Measurement input | 0.127 | 0.129
Loss severity | Residential whole loans, at fair value | Level 3 | Liquidation model | Weighted Average |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Current value of underlying properties | $ 729 | $ 684

X
- Definition Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Acquired During Period At Acquisition At Fair Value Excluding Unsettled Purchases, Simple Average Amount + References No definition available. + Details
Name: | mfa_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAcquiredDuringPeriodAtAcquisitionAtFairValueExcludingUnsettledPurchasesSimpleAverageAmount
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Acquired During Period At Acquisition At Fair Value, Level 3, Excluding Loan Purchase Price + References No definition available. + Details
Name: | mfa_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAcquiredDuringPeriodAtAcquisitionAtFairValueLevel3ExcludingLoanPurchasePrice
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Acquired During Period At Acquisition At Fair Value, Purchases Excluded from Level 3 Fair Value Methodology Disclosures + References No definition available. + Details
Name: | mfa_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAcquiredDuringPeriodAtAcquisitionAtFairValuePurchasesExcludedfromLevel3FairValueMethodologyDisclosures
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair Value Inputs, Annual Change in Home Prices + References No definition available. + Details
Name: | mfa_FairValueInputsAnnualChangeinHomePrices
Namespace Prefix: | mfa_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair Value Inputs, Liquidation Timeline + References No definition available. + Details
Name: | mfa_FairValueInputsLiquidationTimeline
Namespace Prefix: | mfa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair Value Inputs, Value of Underlying Property + References No definition available. + Details
Name: | mfa_FairValueInputsValueofUnderlyingProperty
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Value of input used to measure alternative investment. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_AlternativeInvestmentMeasurementInput
Namespace Prefix: | us-gaap_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_IncomeApproachValuationTechniqueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=mfa_LiquidationModelMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_LoansReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
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: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputDiscountRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputPrepaymentRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputDefaultRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputLossSeverityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |