XML 114 R103.htm IDEA: XBRL DOCUMENT
v3.21.2

Use of Special Purpose Entities and Variable Interest Entities (Loan Securitization Transaction) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2021 | Dec. 31, 2020
Asset-backed Securities, Securitized Loans and Receivables |  |  |
Variable Interest Entity [Line Items] |  |  |
Aggregate unpaid principal balance of residential whole loans sold | $ 3,047,295 | $ 3,047,295 | $ 2,232,561
Outstanding amount of Senior Bonds, at carrying value | 1,514,900 | 1,514,900 | 645,027
Outstanding amount of Senior Bonds, at fair value | 530,829 | 530,829 | 869,482
Outstanding amount of Senior Bonds, total | $ 2,045,729 | $ 2,045,729 | $ 1,514,509
Weighted average interest rate | 1.55% | 1.55% | 2.11%
Weighted average contractual maturity of Senior Bonds |  | 41 years | 41 years
Cash received |  | $ 2,788,354 | $ 1,853,408
Debt issuance cost | $ 7,700 | 7,700 | 3,200
Senior notes |  |  |
Variable Interest Entity [Line Items] |  |  |
Cash received | 277,300 | 1,500,000 |
Senior notes | Asset-backed Securities, Securitized Loans and Receivables |  |  |
Variable Interest Entity [Line Items] |  |  |
Principal amount of Securitized debt | 2,788,383 | 2,788,383 | 1,862,068
Proceeds from Senior bond sold with Step up feature |  | $ 387,600 | 568,700
Debt instrument, coupon step-up period |  | 36 months |
Senior notes | Asset-backed Securities, Securitized Loans and Receivables | Minimum |  |  |
Variable Interest Entity [Line Items] |  |  |
Debt instrument, basis spread on variable rate |  | 1.00% |
Senior notes | Asset-backed Securities, Securitized Loans and Receivables | Maximum |  |  |
Variable Interest Entity [Line Items] |  |  |
Debt instrument, basis spread on variable rate |  | 3.00% |
Senior Support Certificates | Asset-backed Securities, Securitized Loans and Receivables |  |  |
Variable Interest Entity [Line Items] |  |  |
Principal amount of Securitized debt | $ 227,167 | $ 227,167 | $ 268,548

X
- Definition Debt Instrument, Coupon Step-Up Period + References No definition available. + Details
Name: | mfa_DebtInstrumentCouponStepUpPeriod
Namespace Prefix: | mfa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Proceeds From Senior Bonds Sold with Step Up Feature + References No definition available. + Details
Name: | mfa_ProceedsFromSeniorBondsSoldwithStepUpFeature
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Residential Whole Loans, Aggregate Fair Value + References No definition available. + Details
Name: | mfa_ResidentialWholeLoansAggregateFairValue
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Senior Bonds Outstanding, Carrying Value + References No definition available. + Details
Name: | mfa_SeniorBondsOutstandingCarryingValue
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Senior Bonds Outstanding, Fair Value + References No definition available. + Details
Name: | mfa_SeniorBondsOutstandingFairValue
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69C -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69B -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Weighted average interest rate of debt outstanding. + References No definition available. + Details
Name: | us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount, before accumulated amortization, of debt issuance costs classified as noncurrent. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399 + Details
Name: | us-gaap_DeferredFinanceCostsNoncurrentGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6031897-161870 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69C -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69B -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1D -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_SeniorNotesMember
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_DebtInstrumentAxis=mfa_RatedandNonRatedCertificatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |