Assets percentage.

No definition available.

Name:	atax_AssetsPercentage
Namespace Prefix:	atax_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Available for Sale Securities

+ References

No definition available.

+ Details

Name:	atax_NumberOfAvailableForSaleSecurities
Namespace Prefix:	atax_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Available for Sale Securities, Public Housing Authorities

+ References

No definition available.

+ Details

Name:	atax_NumberOfAvailableForSaleSecuritiesPublicHousingAuthorities
Namespace Prefix:	atax_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of partnership securities sold and eliminated.

+ References

No definition available.

+ Details

Name:	atax_NumberOfPartnershipSecuritiesSoldAndEliminated
Namespace Prefix:	atax_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
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

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

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=us-gaap_PartnershipMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=us-gaap_RealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atax_OtherInvestmentsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atax_MortgageBackedSecuritiesInvestmentsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstatePropertiesAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Segment Reporting Footnote Tagging (Details)	12 Months Ended
Segment Reporting Footnote Tagging (Details)	Dec. 31, 2015 Property Unit Integer Segment	Dec. 31, 2013 Segment	Dec. 31, 2014 Security
Segment Reporting Information [Line Items]
Number of Reportable Segments \| Segment	5	5
Number of Available for Sale Securities, Public Housing Authorities	2
Partnership [Member]
Segment Reporting Information [Line Items]
Number of Available for Sale Securities	60
Number of Units in Real Estate Property \| Unit	8,041
Real Estate [Member]
Segment Reporting Information [Line Items]
Number of Units in Real Estate Property \| Unit	2,217
Number of Real Estate Properties \| Property	8
Other Investments [Member]
Segment Reporting Information [Line Items]
Assets percentage	25.00%
MBS Securities Investments [Member]
Segment Reporting Information [Line Items]
Number of partnership securities sold and eliminated. \| Security			3
Variable Interest Entity, Not Primary Beneficiary [Member] \| Partnership [Member]
Segment Reporting Information [Line Items]
Number of Available for Sale Securities	64
Disposal Group Heldforsale Not Discontinued Operations
Segment Reporting Information [Line Items]
Number of Available for Sale Securities	2