XML 61 R50.htm IDEA: XBRL DOCUMENT
v3.20.2

Residential Whole Loans (Additional Credit Related Information) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Sep. 30, 2020 | Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | $ 490,345 |  |  |  |  |  | $ 490,345 |
2019 | 2,091,705 |  |  |  |  |  | 2,091,705 |
2018 | 948,938 |  |  |  |  |  | 948,938 |
2017 | 107,208 |  |  |  |  |  | 107,208 |
2016 | 12,768 |  |  |  |  |  | 12,768 |
Prior | 842,842 |  |  |  |  |  | 842,842 |
Residential whole loans, at carrying value, total or weighted average | 4,493,806 |  |  |  |  |  | 4,493,806 |
Gross write-offs, 2019 |  |  |  |  |  |  | 13 |
Gross write-offs, 2018 |  |  |  |  |  |  | 1,062 |
Gross write-offs, 2017 |  |  |  |  |  |  | 32 |
Gross write-offs, prior |  |  |  |  |  |  | 448 |
Nine Months Ended September 30, 2020 Gross write-offs | 281 | $ 627 | $ 647 | $ 62 | $ 50 | $ 0 | 1,555 |
Net write-offs, 2019 |  |  |  |  |  |  | 13 |
Net write-offs, 2018 |  |  |  |  |  |  | 1,062 |
Net write-offs, 2017 |  |  |  |  |  |  | 32 |
Net write-offs |  |  |  |  |  |  | 448 |
Total Recoveries |  |  |  |  |  |  | 0 |
Nine Months Ended September 30, 2020 Net write-offs |  |  |  |  |  |  | 1,555 |
Purchased Performing Loans | 3,791,792 |  |  |  |  |  | $ 3,791,792 | $ 5,370,653
Ratio Loan-To-Value |  |  |  |  |  |  | 80.00% |
Debt-to-Value Ratio, Less than 80 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 439,607 |  |  |  |  |  | $ 439,607 |
2019 | 2,026,153 |  |  |  |  |  | 2,026,153 |
2018 | 918,394 |  |  |  |  |  | 918,394 |
2017 | 96,397 |  |  |  |  |  | 96,397 |
2016 | 9,432 |  |  |  |  |  | 9,432 |
Prior | 559,803 |  |  |  |  |  | 559,803 |
Residential whole loans, at carrying value, total or weighted average | 4,049,786 |  |  |  |  |  | 4,049,786 |
Debt-to-Value Ratio, 80 to 100 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 50,738 |  |  |  |  |  | 50,738 |
2019 | 65,552 |  |  |  |  |  | 65,552 |
2018 | 30,544 |  |  |  |  |  | 30,544 |
2017 | 10,811 |  |  |  |  |  | 10,811 |
2016 | 3,336 |  |  |  |  |  | 3,336 |
Prior | 283,039 |  |  |  |  |  | 283,039 |
Residential whole loans, at carrying value, total or weighted average | 444,020 |  |  |  |  |  | 444,020 |
Non-QM Loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 428,811 |  |  |  |  |  | 428,811 |
2019 | 1,231,653 |  |  |  |  |  | 1,231,653 |
2018 | 714,188 |  |  |  |  |  | 714,188 |
2017 | 83,973 |  |  |  |  |  | 83,973 |
2016 | 6,523 |  |  |  |  |  | 6,523 |
Prior | 0 |  |  |  |  |  | 0 |
Residential whole loans, at carrying value, total or weighted average | 2,465,148 |  |  |  |  |  | 2,465,148 |
Gross write-offs, 2018 |  |  |  |  |  |  | 32 |
Nine Months Ended September 30, 2020 Gross write-offs |  |  |  |  |  |  | 32 |
Net write-offs, 2018 |  |  |  |  |  |  | 32 |
Nine Months Ended September 30, 2020 Net write-offs |  |  |  |  |  |  | 32 |
Purchased Performing Loans | 2,465,148 |  |  |  |  |  | 2,465,148 | 3,707,245
Non-QM Loans | Debt-to-Value Ratio, Less than 80 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 380,729 |  |  |  |  |  | 380,729 |
2019 | 1,196,185 |  |  |  |  |  | 1,196,185 |
2018 | 684,404 |  |  |  |  |  | 684,404 |
2017 | 74,862 |  |  |  |  |  | 74,862 |
2016 | 6,371 |  |  |  |  |  | 6,371 |
Prior | 0 |  |  |  |  |  | 0 |
Residential whole loans, at carrying value, total or weighted average | 2,342,551 |  |  |  |  |  | 2,342,551 |
Non-QM Loans | Debt-to-Value Ratio, 80 to 100 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 48,082 |  |  |  |  |  | 48,082 |
2019 | 35,468 |  |  |  |  |  | 35,468 |
2018 | 29,784 |  |  |  |  |  | 29,784 |
2017 | 9,111 |  |  |  |  |  | 9,111 |
2016 | 152 |  |  |  |  |  | 152 |
Prior | 0 |  |  |  |  |  | 0 |
Residential whole loans, at carrying value, total or weighted average | 122,597 |  |  |  |  |  | 122,597 |
Rehabilitation loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 37,740 |  |  |  |  |  | 37,740 |
2019 | 558,361 |  |  |  |  |  | 558,361 |
2018 | 94,521 |  |  |  |  |  | 94,521 |
2017 | 9,246 |  |  |  |  |  | 9,246 |
2016 | 0 |  |  |  |  |  | 0 |
Prior | 0 |  |  |  |  |  | 0 |
Residential whole loans, at carrying value, total or weighted average | 699,868 |  |  |  |  |  | 699,868 |
Gross write-offs, 2019 |  |  |  |  |  |  | 13 |
Gross write-offs, 2018 |  |  |  |  |  |  | 1,030 |
Gross write-offs, 2017 |  |  |  |  |  |  | 32 |
Gross write-offs, prior |  |  |  |  |  |  | 0 |
Nine Months Ended September 30, 2020 Gross write-offs |  |  |  |  |  |  | 1,075 |
Net write-offs, 2019 |  |  |  |  |  |  | 13 |
Net write-offs, 2018 |  |  |  |  |  |  | 1,030 |
Net write-offs, 2017 |  |  |  |  |  |  | 32 |
Net write-offs |  |  |  |  |  |  | 0 |
Nine Months Ended September 30, 2020 Net write-offs |  |  |  |  |  |  | 1,075 |
Purchased Performing Loans | 699,868 |  |  |  |  |  | 699,868 | 1,026,097
Rehabilitation loans | Debt-to-Value Ratio, Less than 80 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 36,478 |  |  |  |  |  | 36,478 |
2019 | 542,865 |  |  |  |  |  | 542,865 |
2018 | 93,973 |  |  |  |  |  | 93,973 |
2017 | 7,546 |  |  |  |  |  | 7,546 |
2016 | 0 |  |  |  |  |  | 0 |
Prior | 0 |  |  |  |  |  | 0 |
Residential whole loans, at carrying value, total or weighted average | 680,862 |  |  |  |  |  | 680,862 |
Rehabilitation loans | Debt-to-Value Ratio, 80 to 100 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 1,262 |  |  |  |  |  | 1,262 |
2019 | 15,496 |  |  |  |  |  | 15,496 |
2018 | 548 |  |  |  |  |  | 548 |
2017 | 1,700 |  |  |  |  |  | 1,700 |
2016 | 0 |  |  |  |  |  | 0 |
Prior | 0 |  |  |  |  |  | 0 |
Residential whole loans, at carrying value, total or weighted average | 19,006 |  |  |  |  |  | 19,006 |
Single-family rental loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 23,794 |  |  |  |  |  | 23,794 |
2019 | 301,691 |  |  |  |  |  | 301,691 |
2018 | 140,229 |  |  |  |  |  | 140,229 |
2017 | 13,356 |  |  |  |  |  | 13,356 |
2016 | 0 |  |  |  |  |  | 0 |
Prior | 0 |  |  |  |  |  | 0 |
Residential whole loans, at carrying value, total or weighted average | 479,070 |  |  |  |  |  | 479,070 |
Purchased Performing Loans | 479,070 |  |  |  |  |  | 479,070 | 460,742
Single-family rental loans | Debt-to-Value Ratio, Less than 80 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 22,400 |  |  |  |  |  | 22,400 |
2019 | 287,103 |  |  |  |  |  | 287,103 |
2018 | 140,017 |  |  |  |  |  | 140,017 |
2017 | 13,356 |  |  |  |  |  | 13,356 |
2016 | 0 |  |  |  |  |  | 0 |
Prior | 0 |  |  |  |  |  | 0 |
Residential whole loans, at carrying value, total or weighted average | 462,876 |  |  |  |  |  | 462,876 |
Single-family rental loans | Debt-to-Value Ratio, 80 to 100 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 1,394 |  |  |  |  |  | 1,394 |
2019 | 14,588 |  |  |  |  |  | 14,588 |
2018 | 212 |  |  |  |  |  | 212 |
2017 | 0 |  |  |  |  |  | 0 |
2016 | 0 |  |  |  |  |  | 0 |
Prior | 0 |  |  |  |  |  | 0 |
Residential whole loans, at carrying value, total or weighted average | 16,194 |  |  |  |  |  | 16,194 |
Seasoned performing loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 0 |  |  |  |  |  | 0 |
2019 | 0 |  |  |  |  |  | 0 |
2018 | 0 |  |  |  |  |  | 0 |
2017 | 0 |  |  |  |  |  | 0 |
2016 | 79 |  |  |  |  |  | 79 |
Prior | 147,627 |  |  |  |  |  | 147,627 |
Residential whole loans, at carrying value, total or weighted average | 147,706 |  |  |  |  |  | 147,706 |
Purchased Performing Loans | 147,706 |  |  |  |  |  | 147,706 | 176,569
Seasoned performing loans | Debt-to-Value Ratio, Less than 80 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 0 |  |  |  |  |  | 0 |
2019 | 0 |  |  |  |  |  | 0 |
2018 | 0 |  |  |  |  |  | 0 |
2017 | 0 |  |  |  |  |  | 0 |
2016 | 79 |  |  |  |  |  | 79 |
Prior | 139,538 |  |  |  |  |  | 139,538 |
Residential whole loans, at carrying value, total or weighted average | 139,617 |  |  |  |  |  | 139,617 |
Seasoned performing loans | Debt-to-Value Ratio, 80 to 100 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 0 |  |  |  |  |  | 0 |
2019 | 0 |  |  |  |  |  | 0 |
2018 | 0 |  |  |  |  |  | 0 |
2017 | 0 |  |  |  |  |  | 0 |
2016 | 0 |  |  |  |  |  | 0 |
Prior | 8,089 |  |  |  |  |  | 8,089 |
Residential whole loans, at carrying value, total or weighted average | 8,089 |  |  |  |  |  | 8,089 |
Purchased Credit Deteriorated Loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 0 |  |  |  |  |  | 0 |
2019 | 0 |  |  |  |  |  | 0 |
2018 | 0 |  |  |  |  |  | 0 |
2017 | 633 |  |  |  |  |  | 633 |
2016 | 6,166 |  |  |  |  |  | 6,166 |
Prior | 695,215 |  |  |  |  |  | 695,215 |
Residential whole loans, at carrying value, total or weighted average | 702,014 |  |  |  |  |  | 702,014 |
Gross write-offs, prior |  |  |  |  |  |  | 448 |
Nine Months Ended September 30, 2020 Gross write-offs |  |  |  |  |  |  | 448 |
Net write-offs |  |  |  |  |  |  | 448 |
Total Recoveries |  |  |  |  |  |  | 0 |
Nine Months Ended September 30, 2020 Net write-offs |  |  |  |  |  |  | 448 |
Purchased Credit Deteriorated Loans | Debt-to-Value Ratio, Less than 80 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 0 |  |  |  |  |  | 0 |
2019 | 0 |  |  |  |  |  | 0 |
2018 | 0 |  |  |  |  |  | 0 |
2017 | 633 |  |  |  |  |  | 633 |
2016 | 2,982 |  |  |  |  |  | 2,982 |
Prior | 420,265 |  |  |  |  |  | 420,265 |
Residential whole loans, at carrying value, total or weighted average | 423,880 |  |  |  |  |  | 423,880 |
Purchased Credit Deteriorated Loans | Debt-to-Value Ratio, 80 to 100 Percent |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
2020 | 0 |  |  |  |  |  | 0 |
2019 | 0 |  |  |  |  |  | 0 |
2018 | 0 |  |  |  |  |  | 0 |
2017 | 0 |  |  |  |  |  | 0 |
2016 | 3,184 |  |  |  |  |  | 3,184 |
Prior | 274,950 |  |  |  |  |  | 274,950 |
Residential whole loans, at carrying value, total or weighted average | 278,134 |  |  |  |  |  | 278,134 |
Settled Whole Loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
Residential whole loans, at carrying value, total or weighted average | 4,387,559 |  |  |  |  |  | 4,387,559 | 6,066,345
Settled Whole Loans | Non-QM Loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
Purchased Performing Loans | 2,438,395 |  |  |  |  |  | $ 2,438,395 | 3,706,857
Ratio Loan-To-Value |  |  | 67.00% |  |  |  | 64.00% |
Settled Whole Loans | Rehabilitation loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
Purchased Performing Loans | 677,235 |  |  |  |  |  | $ 677,235 | 1,023,766
Ratio Loan-To-Value |  |  | 64.00% |  |  |  | 63.00% |
Settled Whole Loans | Single-family rental loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
Purchased Performing Loans | 474,045 |  |  |  |  |  | $ 474,045 | 460,679
Ratio Loan-To-Value |  |  | 70.00% |  |  |  | 70.00% |
Settled Whole Loans | Seasoned performing loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
Purchased Performing Loans | 147,556 |  |  |  |  |  | $ 147,556 | 176,569
Ratio Loan-To-Value |  |  | 46.00% |  |  |  | 41.00% |
Settled Whole Loans | Certain Rehabilitation Loans |  |  |  |  |  |  |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |  |  |  |  |  |  |
Purchased Performing Loans | $ 222,200 |  |  |  |  |  | $ 222,200 | $ 269,200
Ratio Loan-To-Value |  |  | 69.00% |  |  |  | 68.00% |

X
- Definition Financing Receivable, Originated Five or More Years before Latest Fiscal Year, Gross Write-Offs + References No definition available. + Details
Name: | mfa_FinancingReceivableOriginatedFiveorMoreYearsbeforeLatestFiscalYearGrossWriteOffs
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Financing Receivable, Originated Five or More Years before Latest Fiscal Year, Net Write-Offs + References No definition available. + Details
Name: | mfa_FinancingReceivableOriginatedFiveorMoreYearsbeforeLatestFiscalYearNetWriteOffs
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Financing Receivable, Originated In Fiscal Year Before Fiscal Year, Gross Write-Offs + References No definition available. + Details
Name: | mfa_FinancingReceivableOriginatedInFiscalYearBeforeFiscalYearGrossWriteOffs
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Financing Receivable, Originated In Fiscal Year before Latest Fiscal Year, Net Write-Offs + References No definition available. + Details
Name: | mfa_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYearNetWriteOffs
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Financing Receivable, Originated Three Years before Latest Fiscal Year, Gross Write-Offs + References No definition available. + Details
Name: | mfa_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYearGrossWriteOffs
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Financing Receivable, Originated Three Years before Latest Fiscal Year, Net Write-Offs + References No definition available. + Details
Name: | mfa_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYearNetWriteOffs
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Financing Receivable, Originated Two Years before Latest Fiscal Year, Gross Write-Offs + References No definition available. + Details
Name: | mfa_FinancingReceivableOriginatedTwoYearsbeforeLatestFiscalYearGrossWriteOffs
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Financing Receivable, Originated Two Years before Latest Fiscal Year, Net Write-Offs + References No definition available. + Details
Name: | mfa_FinancingReceivableOriginatedTwoYearsbeforeLatestFiscalYearNetWriteOffs
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Purchased Performing Loans + References No definition available. + Details
Name: | mfa_PurchasedPerformingLoans
Namespace Prefix: | mfa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The LTV of which the Company has assessed its residential whole loans at carrying value will have a higher likelihood of default than newly originated mortgage loans + References No definition available. + Details
Name: | mfa_RatioLoanToValue
Namespace Prefix: | mfa_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after recovery, of writeoff of financing receivable, charged against allowance for credit loss. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase in allowance for credit loss on financing receivable from recovery. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(4) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of writeoff of financing receivable, charged against allowance for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of financing receivable originated more than five years prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of financing receivable originated four years prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of financing receivable originated in current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of financing receivable originated in fiscal year prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919232-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 + Details
Name: | us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of financing receivable originated three years prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of financing receivable originated two years prior to current fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919232-210447 + Details
Name: | us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear
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_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, before allowance for credit loss, of financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919230-210447 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 80 -URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922355-210448 + Details
Name: | us-gaap_NotesReceivableGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_LoanToValueAxis=us-gaap_LtvLessThan80PercentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanToValueAxis=us-gaap_Ltv80To100PercentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mfa_SettledWholeLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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