Subsequent Events - Schedule of MRB Redeemed (Details)	1 Months Ended
Jul. 31, 2021 USD ($) Unit	Jun. 30, 2021 USD ($) Unit
Debt Instrument [Line Items]
Units \| Unit		4,044
Mortgage Revenue Bonds [Member]
Debt Instrument [Line Items]
Principal Outstanding at Date of Redemption		$ 7,385,000
Mortgage Revenue Bonds [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Principal Outstanding at Date of Redemption	$ 32,380,074
Mortgage Revenue Bonds [Member] \| Rosewood Townhomes [Member] \| Subsequent Event [Member] \| Series A [Member] \| SC [Member]
Debt Instrument [Line Items]
Month Redeemed	July
Units \| Unit	100
Maturity Date	Jul. 01, 2055
Interest Rate	5.75%
Principal Outstanding at Date of Redemption	$ 9,259,206
Mortgage Revenue Bonds [Member] \| Rosewood Townhomes [Member] \| Subsequent Event [Member] \| Series B [Member] \| SC [Member]
Debt Instrument [Line Items]
Month Redeemed	July
Units \| Unit	100
Maturity Date	Aug. 01, 2055
Interest Rate	12.00%
Principal Outstanding at Date of Redemption	$ 469,781
Mortgage Revenue Bonds [Member] \| South Pointe Apartments [Member] \| Subsequent Event [Member] \| Series A [Member] \| SC [Member]
Debt Instrument [Line Items]
Month Redeemed	July
Units \| Unit	256
Maturity Date	Jul. 01, 2055
Interest Rate	5.75%
Principal Outstanding at Date of Redemption	$ 21,551,600
Mortgage Revenue Bonds [Member] \| South Pointe Apartments [Member] \| Subsequent Event [Member] \| Series B [Member] \| SC [Member]
Debt Instrument [Line Items]
Month Redeemed	July
Units \| Unit	256
Maturity Date	Aug. 01, 2055
Interest Rate	12.00%
Principal Outstanding at Date of Redemption	$ 1,099,487

Investment owned, redemption month.

No definition available.

Name:	atax_InvestmentOwnedRedemptionMonth
Namespace Prefix:	atax_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Mortgage loans on real estate, redemption, face amount.

+ References

No definition available.

+ Details

Name:	atax_MortgageLoansOnRealEstateRedemptionFaceAmount
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Maturity date of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column C
-Subsection 29

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Column C))
-URI http://asc.fasb.org/extlink&oid=120402547&loc=d3e617274-123014

+ Details

Name:	srt_MortgageLoanOnRealEstateFinalMaturityDate
Namespace Prefix:	srt_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest rate of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column B
-Subsection 29

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Column B))
-URI http://asc.fasb.org/extlink&oid=120402547&loc=d3e617274-123014

+ Details

Name:	srt_MortgageLoansOnRealEstateInterestRate
Namespace Prefix:	srt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

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

- Definition

The number of units in a real estate property owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfUnitsInRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_InvestmentTypeAxis=atax_MortgageRevenueBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=us-gaap_FirstMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_SC
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=us-gaap_SecondMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=atax_SouthPointeApartmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: