XML 73 R50.htm IDEA: XBRL DOCUMENT
v3.19.3

Residential Mortgage Securities and MSR-Related Assets (MSR Related Assets - Narrative) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Sep. 30, 2019 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018 | Mar. 31, 2018 | Dec. 31, 2016
Term notes backed by MSR-related collateral |  |  |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |  |  |
Term notes backed by MSR related collateral | $ 1,104,130 | $ 1,104,130 |  | $ 538,499 |  |
Amortized costs | 1,100,000 | 1,100,000 |  | 538,500 |  |
Gross unrealized gains | 5,400 | $ 5,400 |  | $ 7 |  |
Weighted average yield |  | 4.99% | 5.32% |  |  |
Weighted average to maturity |  | 5 years 8 months 12 days | 4 years 8 months 12 days |  |  |
Corporate Loan |  |  |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |  |  |
Commitment to lend | 100,000 | $ 100,000 |  |  |  | $ 130,000
Amount drawn | $ 60,200 | $ 60,200 |  |  | $ 124,200 |
Interest coupon rate | 5.39% | 5.39% |  |  |  |
Debt term |  | 11 months |  |  |  |
Commitment period on undrawn amount | 11 months |  |  |  |  |
Minimum | Corporate Loan |  |  |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |  |  |
Commitment fee on undrawn amount | 0.25% | 0.25% |  |  |  |
Maximum | Corporate Loan |  |  |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |  |  |
Commitment fee on undrawn amount | 1.00% | 1.00% |  |  |  |

X
- Definition Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, Amortized Costs + References No definition available. + Details
Name: | mfa_FinancialInstrumentsOwnedMortgagesMortgagebackedandAssetbackedSecuritiesAmortizedCosts
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, Gross Unrealized Gains + References No definition available. + Details
Name: | mfa_FinancialInstrumentsOwnedMortgagesMortgagebackedandAssetbackedSecuritiesGrossUnrealizedGains
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, Weighted Average Yield + References No definition available. + Details
Name: | mfa_FinancialInstrumentsOwnedMortgagesMortgagebackedandAssetbackedSecuritiesWeightedAverageYield
Namespace Prefix: | mfa_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financial Instruments, Owned, Mortgages, Mortgage-backed and Asset-backed Securities, Weighted Average to Maturity + References No definition available. + Details
Name: | mfa_FinancialInstrumentsOwnedMortgagesMortgagebackedandAssetbackedSecuritiesWeightedAveragetoMaturity
Namespace Prefix: | mfa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financing Receivable, Amount Drawn + References No definition available. + Details
Name: | mfa_FinancingReceivableAmountDrawn
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing Receivable, Commitment Fee Income Rate + References No definition available. + Details
Name: | mfa_FinancingReceivableCommitmentFeeIncomeRate
Namespace Prefix: | mfa_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Financing Receivable, Commitment Period on Undrawn Amount + References No definition available. + Details
Name: | mfa_FinancingReceivableCommitmentPeriodonUndrawnAmount
Namespace Prefix: | mfa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financing Receivable, Commitment to Lend + References No definition available. + Details
Name: | mfa_FinancingReceivableCommitmenttoLend
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing Receivable, Interest Coupon Rate + References No definition available. + Details
Name: | mfa_FinancingReceivableInterestCouponRate
Namespace Prefix: | mfa_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Financing Receivable, Remaining Term + References No definition available. + Details
Name: | mfa_FinancingReceivableRemainingTerm
Namespace Prefix: | mfa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The fair value as of the balance sheet date of firm holdings in mortgages, mortgage backed securities (investment instruments that represent ownership of an undivided interest in a group of mortgages, where principal and interest from the individual mortgages are used to pay investors' principal and interest on the mortgage backed security) and asset-backed securities that are primarily paid from the cash flows of a discrete pool of receivables or other financial assets (such as credit-card receivables), either fixed or revolving, that by their terms convert into cash within a finite time period. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969 + Details
Name: | us-gaap_FinancialInstrumentsOwnedMortgagesMortgageBackedAndAssetBackedSecuritiesAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=mfa_CorporateLoanMember
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: |