XML 54 R41.htm IDEA: XBRL DOCUMENT v3.22.0.1

Summary of Significant Accounting Policies - Residential Whole Loans (Details)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Number of days considered to classify loans delinquent	60 days
Weighted Average LTV Ratio	80.00%

X

- Definition

Represents the number of days considered to classify loans delinquent.

+ References

No definition available.

+ Details

Name:	mfa_NumberOfDaysConsideredToClassifyLoansDelinquent
Namespace Prefix:	mfa_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_AccountingPoliciesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration