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

Available-for-sale security, maturity date at a point in time.

No definition available.

Name:	atax_AvailableForSaleSecurityMaturityDateAtPointInTime
Namespace Prefix:	atax_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

No definition available.

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

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.

No definition available.

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

Name:	dei_EntityByLocationAxis=atax_ProNova2014BMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_EntityByLocationAxis=atax_CompanionAtThornHillApartmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_AuctionMarketPreferredSecuritiesStockSeriesAxis=us-gaap_SeriesAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_EntityByLocationAxis=atax_AvistarAtCopperfieldSeriesAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_EntityByLocationAxis=atax_AvistarAtWilcrestSeriesAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_EntityByLocationAxis=atax_AvistarAtWoodHollowSeriesAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: