Real Estate Assets Variable Interest Entities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Land and improvements	$ 15,590,493us-gaap_LandAndLandImprovements	$ 15,589,893us-gaap_LandAndLandImprovements
Buildings and improvements	132,000,442	131,910,221
Carrying Value at September 30, 2012	147,590,935us-gaap_PropertyPlantAndEquipmentGross	147,500,114us-gaap_PropertyPlantAndEquipmentGross
VIE Property, Plant and Equipment, Gross	23,093,876atax_ViePropertyPlantAndEquipmentGross	23,040,448atax_ViePropertyPlantAndEquipmentGross
Accumulated Depreciation - VIES	(10,814,129)atax_AccumulatedDepreciationVies	(10,583,646)atax_AccumulatedDepreciationVies
VIE Property Property, Plant and Equipment, Net	12,279,747	12,456,802
Bent Tree [Member]
Property, Plant and Equipment [Line Items]
Number of Units	232	232
Land and improvements	986,000	986,000
Buildings and improvements	12,348,139	12,303,982
Carrying Value at September 30, 2012	13,334,139	13,289,982
Fairmont Oaks [Member]
Property, Plant and Equipment [Line Items]
Number of Units	178	178
Land and improvements	850,400	850,400
Buildings and improvements	8,909,337	8,900,066
Carrying Value at September 30, 2012	$ 9,759,737	$ 9,750,466

Accumulated Depreciation - VIES - Accumulated Depreciation for VIEs in reporting period

No definition available.

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Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

Gross amount, at the balance sheet date, of long-lived physical assets used in the normal conduct of business and not intended for resale. This can include buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References

No definition available.

+ Details

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

- Definition

VIE Property, Plant and Equipment, Gross

+ References

No definition available.

+ Details

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

- Definition

VIE Property Property, Plant and Equipment, Net

+ References

No definition available.

+ Details

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

- Definition

Amount before accumulated deprecation and depletion of real estate held for productive use and additions or improvements to real estate held for productive use, examples include, but are not limited to, walkways, driveways, fences, and parking lots. Excludes land held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6812-107765

+ Details

Name:	us-gaap_LandAndLandImprovements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.13)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	debit
Period Type:	instant

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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