Debt Financing Contractual Maturities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Debt Financing, Current Maturities	$ 84,172,098atax_DebtFinancingCurrentMaturities
Debt Financing, Maturities, Repayment of Principal in Year Two	24,872,528
Debt Financing, Maturities, Repayments of Principal in Year Three	143,627,104
Debt Financing, Maturities, Repayments of Principal in Year Four	1,217,740
Debt Financing, Maturities, Repayments of Principal in Year Five	125,418,023
Debt Financing, Maturities, Repayments of Principal after Year Five	0
Debt financing	$ 379,307,493atax_DebtFinancing	$ 345,359,000atax_DebtFinancing

Long-term debt financing provided through the securitization of tax-exempt mortgage revenue bonds.

No definition available.

Name:	atax_DebtFinancing
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long-term debt financing provided through the securitization of tax-exempt mortgage revenue bonds scheduled to be repaid within one year .

+ References

No definition available.

+ Details

Name:	atax_DebtFinancingCurrentMaturities
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long-term debt financing provided through the securitization of tax-exempt mortgage revenue bonds maturing in the second fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	atax_DebtFinancingMaturitiesRepaymentOfPrincipalInYearTwo
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long-term debt financing provided through the securitization of tax-exempt mortgage revenue bonds maturing after the fifth year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	atax_DebtFinancingMaturitiesRepaymentsOfPrincipalAfterYearFive
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long-term debt finanicng provided through the securitization of tax=exempt mortgage revenue bonds maturing in the fifth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	atax_DebtFinancingMaturitiesRepaymentsOfPrincipalInYearFive
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long-term debt financing provided through the securitization of tax-exempt mortgage revenue bonds maturing in the fouth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	atax_DebtFinancingMaturitiesRepaymentsOfPrincipalInYearFour
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Long-term debt financing provided through the securitization of tax-exempt mortgage revenue bonds maturing in the third fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	atax_DebtFinancingMaturitiesRepaymentsOfPrincipalInYearThree
Namespace Prefix:	atax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant