XML 78 R65.htm IDEA: XBRL DOCUMENT
v3.22.1

Other Assets - TBA Securities (Details) - USD ($) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2022 | Dec. 31, 2021
Derivative [Line Items] |  |
Notional Amount | $ 2,400,000,000 |
TBA Securities | Short |  |
Derivative [Line Items] |  |
Aggregate value | 5,800,000 | $ (1,300,000)
Gain on derivative | 18,900,000 |
FNCL 2.5 | Short |  |
Derivative [Line Items] |  |
Notional Amount | 180,000,000 | 180,000,000
FNCL 2 | Short |  |
Derivative [Line Items] |  |
Notional Amount | $ 130,000,000 | $ 130,000,000

X
- Definition Amount of increase in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5618551-113959 + Details
Name: | us-gaap_DerivativeGainOnDerivative
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Aggregate net fair value of all derivative instruments designated as hedging instruments. Includes instruments designated as cash flow hedges, fair value hedges, and hedges of net investments in foreign operations. + References No definition available. + Details
Name: | us-gaap_DerivativeInstrumentsInHedgesAtFairValueNet
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_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mfa_TBASecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mfa_FNCL25Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=mfa_FNCL2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |