Derivative, Maturity Date at a point in time

No definition available.

Name:	atax_DerivativeMaturityDateAtPointInTime
Namespace Prefix:	atax_
Data Type:	xbrli:dateItemType
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Period Type:	duration

- Definition

Deriviative at purchase price - The amount paid for the deriviative when it was purchased.

+ References

No definition available.

+ Details

Name:	atax_DeriviativeAtPurchasePrice
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of derivatives.

+ References

No definition available.

+ Details

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Namespace Prefix:	atax_
Data Type:	xbrli:integerItemType
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Period Type:	duration

- Definition

The date when a document, upon receipt and acceptance, becomes officially effective, in CCYY-MM-DD format. Usually it is a system-assigned date time value, but it may be declared by the submitter in some cases.

+ References

No definition available.

+ Details

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Namespace Prefix:	dei_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Nominal or face amount used to calculate payments on the derivative asset.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5580258-113959

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5579245-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

+ Details

Name:	us-gaap_DerivativeAssetNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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

- Definition

Amount of increase in the fair value of derivatives recognized in the income statement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5618551-113959

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (a),(c),(d),(e)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

+ Details

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

- Details

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

- Definition

Amount of decrease in the fair value of derivatives recognized in the income statement.

+ References

+ Details

Name:	us-gaap_DerivativeLossOnDerivative
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Date the derivative contract matures, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeMaturityDates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow for derivative instruments during the period, which are classified as investing activities, excluding those designated as hedging instruments.

+ References

No definition available.

+ Details

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

- Details

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- Details

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- Details

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- Details

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- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_SwapMember
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Interest Rate Derivative Agreements Footnote Tagging (Details) (USD $)	3 Months Ended
	Mar. 31, 2015 derivatives	Mar. 31, 2014	Dec. 31, 2014
Derivative [Line Items]
Number of Derivatives	9atax_NumberOfDerivatives
Derivative, Loss on Derivative	$ 900,000us-gaap_DerivativeLossOnDerivative	$ 176,000us-gaap_DerivativeLossOnDerivative
Payments for Derivative Instrument, Investing Activities	(10,500)	391,500
SMBC Capital Markets, Inc 1 and 2 [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	52,300,000		70,000,000
Derivative, Maturity Date at a point in time	Mar. 01, 2017
Derivative, Fixed Interest Rate	1.00%
Deriviative at purchase price	369,500
SMBC Capital Markets, Inc-2 [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	11,000,000
Derivative, Maturity Date at a point in time	Mar. 01, 2017
Payments for Derivative Instrument, Investing Activities	0
Derivative, Fixed Interest Rate	1.00%
Deriviative at purchase price	150,500
Deutsche Bank [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	93,305,000
Derivative, Maturity Date at a point in time	Sep. 01, 2017
Derivative, Fixed Interest Rate	1.50%
Deriviative at purchase price	793,000
Swap [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	2.00%
Decatur-Angle [Member] \| Swap [Member]
Derivative [Line Items]
Derivative, Gain on Derivative	646,000
Derivative, Notional Amount	23,000,000
Document Effective Date	Oct. 15, 2016
Derivative, Maturity Date	Oct. 15, 2021
Bruton Apartments [Member] \| Swap [Member]
Derivative [Line Items]
Derivative, Loss on Derivative	520,000
Derivative, Notional Amount	$ 18,100,000
Document Effective Date	Apr. 15, 2017
Derivative, Maturity Date	Apr. 15, 2022