Assets percentage.

No definition available.

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

- Definition

Long-term debt financing provided through the securitization of tax-exempt mortgage revenue bonds.

+ References

No definition available.

+ Details

Name:	atax_DebtFinancing
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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, held in a trust.

+ References

No definition available.

+ Details

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

- Definition

Number of collateralized securities.

+ References

No definition available.

+ Details

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

- 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

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26853-111562

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=atax_TOBFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialRealEstateMember
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_StatementBusinessSegmentsAxis=atax_MortgageRevenueBondInvestmentsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageMember
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:	dei_EntityByLocationAxis=atax_WoodlandParkMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Segment Reporting Footnote Tagging (Details)	1 Months Ended		6 Months Ended
Segment Reporting Footnote Tagging (Details)	May 31, 2016 USD ($)	Jan. 31, 2016 USD ($) Integer Security	Jun. 30, 2016 USD ($) Property Unit Integer Segment	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments \| Segment			5
Proceeds from Sale of Available-for-sale Securities \| $	$ 5,200,000	$ 15,000,000	$ 9,295,000
Number of Available for Sale Securities, Held in a Trust		3
Debt financing \| $			$ 430,063,339	$ 451,496,716
TOB Facility [Member]
Segment Reporting Information [Line Items]
Debt financing \| $		$ 11,900,000
Other Investments [Member]
Segment Reporting Information [Line Items]
Assets percentage			25.00%
Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Number of collateralized securities			1
MBS Securities Investments [Member]
Segment Reporting Information [Line Items]
Number of partnership securities sold and eliminated. \| Security		3
Mortgage Revenue Bond Investments Segment [Member]
Segment Reporting Information [Line Items]
Number of Available for Sale Securities			64
Mortgage Revenue Bond Investments Segment [Member] \| Residential Properties [Member]
Segment Reporting Information [Line Items]
Number of Available for Sale Securities			63
Units \| Unit			8,784
Real Estate [Member]
Segment Reporting Information [Line Items]
Units \| Unit			1,847
Number of Real Estate Properties \| Property			6
Real Estate [Member] \| Woodland Park [Member]
Segment Reporting Information [Line Items]
Units \| Unit			236