Adverse change rate - effective rate if 10% adverse change in market occurs

No definition available.

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

- Definition

This item represents the gross unrealized losses for securities held in trust, at a point in time, which are categorized neither as held-to-maturity nor trading securities. These are for the Public Housing Trusts.

+ References

No definition available.

+ Details

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

- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. This does not include premiums.

+ References

No definition available.

+ Details

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

- Definition

The percentage of ownership of available-for-sale securities.

+ References

No definition available.

+ Details

Name:	atax_AvailableForSaleSecuritiesOwnershipPercentage
Namespace Prefix:	atax_
Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Effective rate - the effective rate for the available for sale securities held in the portfolio

+ References

No definition available.

+ Details

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

- Definition

Number of Available for Sale Securities, Public Housing Authorities

+ References

No definition available.

+ Details

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

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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

- Definition

The cash inflow associated with maturities (principal being due), prepayments and calls (requests of early payments) on securities not classified as either held-to-maturity securities or trading securities which are classified as available-for-sale securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26853-111562

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_DebtSecurityAxis=atax_LifersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InformationByCategoryOfDebtSecurityAxis=atax_A10AdverseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atax_TrustPortfolioPhcftMember
Namespace Prefix:
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Public Housing Capital Fund Trusts Narrative Tagging (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities	$ 202,888	$ 1,778,734
Available for Sale Securities, not Including Premiums			59,308,398
Available-for-Sale Securities, Ownership Percentage	100.00%
Adverse change rate	10.00%atax_AdverseChangeRate
Public housing capital fund trusts [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt, Weighted Average Interest Rate	5.00%
Number of Available for Sale Securities, Public Housing Authorities	3
Available for Sale Securities, not Including Premiums	59,308,398
Unrealized Loss	(85,487)		0
LIFERS [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-Sale Securities, Ownership Percentage	100.00%
Effective rate - minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Effective rate	4.80%		4.70%
Effective rate - minimum [Member] \| Public housing capital fund trusts [Member]
Schedule of Available-for-sale Securities [Line Items]
Effective rate	4.20%
Effective rate - maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Effective rate	9.60%		8.30%
Effective rate - maximum [Member] \| Public housing capital fund trusts [Member]
Schedule of Available-for-sale Securities [Line Items]
Effective rate	5.40%
10% adverse [Member] \| Public housing capital fund trusts [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Loss	$ 2,300,000
10% adverse [Member] \| Effective rate - minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Effective rate	5.20%
10% adverse [Member] \| Effective rate - minimum [Member] \| Public housing capital fund trusts [Member]
Schedule of Available-for-sale Securities [Line Items]
Effective rate	4.90%
10% adverse [Member] \| Effective rate - maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Effective rate	10.50%
10% adverse [Member] \| Effective rate - maximum [Member] \| Public housing capital fund trusts [Member]
Schedule of Available-for-sale Securities [Line Items]
Effective rate	6.30%