Derivative at purchase price - The amount paid for the derivative when it was purchased.

No definition available.

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

- Definition

Derivative, Maturity Date at a point in time

+ References

No definition available.

+ Details

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

- Definition

Number of derivatives.

+ References

No definition available.

+ Details

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- 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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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

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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 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5579245-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Notional Amount
-URI http://asc.fasb.org/extlink&oid=6519104

Reference 3: 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=56946850&loc=SL5580258-113959

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226016-175313

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=d3e41678-113959

+ Details

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

- Definition

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(c)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624163-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226000-175313

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=51814546&loc=SL51823488-111719

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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 4C
-Subparagraph (a),(c),(d),(e)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5618551-113959

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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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

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=56946850&loc=SL5618551-113959

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-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=56946850&loc=SL5624171-113959

+ Details

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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

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	dei_EntityByLocationAxis=atax_DecaturAngleMember
Namespace Prefix:
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Balance Type:
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- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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Interest Rate Derivatives Footnote Tagging (Details)	1 Months Ended		12 Months Ended
Interest Rate Derivatives Footnote Tagging (Details)	Jul. 31, 2014 USD ($)	Feb. 28, 2014 USD ($)	Dec. 31, 2015 USD ($) Derivative	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Derivative [Line Items]
Number of Derivatives \| Derivative			12
Derivative, Loss on Derivative			$ 1,800,000	$ 2,000,000	$ 284,000
Derivative Asset, Fair Value, Gross Asset			$ 344,000	268,000
Swap [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate			2.00%
Decatur-Angle [Member] \| Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount			$ 23,000,000
Document Effective Date			Oct. 15, 2016
Derivative, Maturity Date			Oct. 15, 2021
Derivative, Gain on Derivative			$ 737,000
Bruton Apartments [Member] \| Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount			$ 18,100,000
Document Effective Date			Apr. 15, 2017
Derivative, Maturity Date			Apr. 15, 2022
Derivative, Loss on Derivative			$ 580,000
Wells Fargo Bank, Royal Bank of Canada-3, SMBC Capital Markets, Inc-4 [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount			$ 28,100,000
Derivative, Fixed Interest Rate			3.00%
Derivative at purchase price			$ 573,000
SMBC Capital Markets, Inc-2 [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount			$ 11,000,000	$ 28,800,000
Derivative, Fixed Interest Rate			1.00%
Derivative at purchase price			$ 150,500
Derivative, Maturity Date at a point in time			Mar. 01, 2017
SMBC Capital Markets, Inc 1 and 2 [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount		$ 70,000,000	$ 52,300,000
Derivative, Fixed Interest Rate		1.00%
Derivative at purchase price		$ 390,000	$ 151,000
Derivative, Maturity Date at a point in time		Mar. 01, 2017	Mar. 01, 2017
Derivative, Collateral, Right to Reclaim Cash			$ 10,500
Barclays Bank PLC 1, Royal Bank of Canada-2 and SMBC Capital Markets, Inc-3 [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 31,600,000
Derivative, Fixed Interest Rate	3.00%
Derivative at purchase price	$ 991,000
Derivative, Maturity Date at a point in time	Aug. 15, 2019