Available-for-Sale Securities, Asset Ownership - Ownership percentage of underlying asset

No definition available.

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

- Definition

Available-for-sale Security, Maturity Date at a point in time

+ References

No definition available.

+ Details

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

- Definition

Limited Partners - Limited Partners related to sale of underlyting real estate

+ References

No definition available.

+ Details

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

- Definition

Percent of contribution - ownership percentage and contribution

+ References

No definition available.

+ Details

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

- Definition

The difference between the sale price or salvage price and the book value of a property, plant, and equipment asset that was sold or retired during the reporting period. This element refers to the gain (loss).

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainLossOnSaleOfPropertyPlantEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

- Details

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

- Definition

Revenue from the sale of commercial, industrial, or residential property during the period. This element is more likely than not relevant to an entity for which real estate operations are a principal activity. If real estate operations are not a principal activity, the reporting entity would likely use a gain (loss) on sale of property, plant, or equipment type element.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(e))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 66

-Paragraph 44, 45

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_SalesOfRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Partnership Income, Expense and Cash Distributions MF Properties (Details) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2010	Oct. 31, 2011 entities	Jun. 29, 2010	Jun. 30, 2012 Consolidated Properties [Member] properties	Jun. 30, 2010 Consolidated Properties [Member] properties	Jun. 30, 2012 Consolidated Properties Subject to Sale [Member] properties	Dec. 31, 2011 Consolidated Properties Subject to Sale [Member] limited	Oct. 31, 2011 Consolidated Properties Subject to Sale [Member] properties	Jun. 30, 2010 Consolidated Properties Subject to Sale [Member] properties	Jun. 30, 2012 Limited Partner [Member] Consolidated Properties [Member] properties	Jun. 30, 2010 Limited Partner [Member] Consolidated Properties [Member] properties
Real Estate Properties [Line Items]
Available-for-sale Security, Maturity Date at a point in time											Jun. 30, 2050
Sales of Real Estate			$ 16,200,000
Gain (Loss) on Sale of Property Plant Equipment	$ 0	$ 21,103	$ 1,800,000
Available-for-Sale Securities, Asset Ownership			100.00%		99.00%
Number of Real Estate Properties						9	4	3		3	3	5	4
Percent of contribution			100.00%
Limited Partners				2					3