Variable Interest Entities Consolidating Balance Sheet (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets [Abstract]
Cash and cash equivalents	$ 49,193,343	$ 11,318,015
Restricted cash	11,685,729	6,845,543
Interest receivable	4,121,486us-gaap_InterestReceivable	3,342,038us-gaap_InterestReceivable
Available-for-sale Securities, Fair Value Disclosure Held in Trust	378,423,092	216,371,801
Available-for-sale Securities	70,601,045us-gaap_AvailableForSaleSecurities	68,946,370us-gaap_AvailableForSaleSecurities
Public housing capital fund trusts, at fair value	61,263,123	62,056,379
Mortgage backed securities, at fair value	14,841,558	37,845,661
Real Estate Assets [Abstract]
Land and land improvements	15,589,893us-gaap_LandAndLandImprovements	11,081,992us-gaap_LandAndLandImprovements
Buildings and improvements	131,910,221	111,195,695
Real estate assets before accumulated depreciation	147,500,114us-gaap_PropertyPlantAndEquipmentGross	122,277,687us-gaap_PropertyPlantAndEquipmentGross
Accumulated depreciation	(24,691,800)	(19,128,753)
Net real estate assets	122,808,314us-gaap_PropertyPlantAndEquipmentNet	103,148,934us-gaap_PropertyPlantAndEquipmentNet
Other Assets	31,301,527us-gaap_OtherAssets	24,358,291us-gaap_OtherAssets
Assets	744,239,217us-gaap_Assets	534,233,032us-gaap_Assets	413,150,755us-gaap_Assets
Liabilities
Accounts payable, accrued expenses and other liabilities	4,627,089	5,450,694
Dividends Payable, Current	7,617,390us-gaap_DividendsPayableCurrent	6,446,076us-gaap_DividendsPayableCurrent
Debt financing	345,359,000atax_DebtFinancing	257,274,000atax_DebtFinancing
Long-term Debt	76,707,834us-gaap_LongTermDebt	57,087,320us-gaap_LongTermDebt
Bond Purchase Commitment - Fair Market Value Adjustment - Liability	0	4,852,177
Liabilities	434,311,313us-gaap_Liabilities	331,110,267us-gaap_Liabilities
Partners' Capital
General Partner	578,238us-gaap_GeneralPartnersCapitalAccount	16,671us-gaap_GeneralPartnersCapitalAccount
Beneficial Unit Certificate holders	330,457,117us-gaap_LimitedPartnersCapitalAccount	223,573,312us-gaap_LimitedPartnersCapitalAccount
Unallocated deficit of Consolidated VIEs	(21,091,456)	(20,455,896)
Partners' Capital	309,943,899us-gaap_PartnersCapital	203,134,087us-gaap_PartnersCapital	181,917,192us-gaap_PartnersCapital
Partners' Capital Attributable to Noncontrolling Interest	(15,995)	(11,322)
Total Capital	309,927,904	203,122,765	183,970,931	131,589,045
Total Liabilities and Partners' Capital	744,239,217	534,233,032
Partnership [Member]
Assets [Abstract]
Cash and cash equivalents	49,157,571	11,292,039
Restricted cash	11,141,496	6,344,666
Interest receivable	4,791,828	5,281,398
Available-for-sale Securities, Fair Value Disclosure Held in Trust	394,568,208	230,885,864
Available-for-sale Securities	70,601,045	68,946,370
Public housing capital fund trusts, at fair value	61,263,123	62,056,379
Mortgage backed securities, at fair value	14,841,558	37,845,661
Real Estate Assets [Abstract]
Land and land improvements	13,753,493	9,245,592
Buildings and improvements	110,706,173	90,253,256
Real estate assets before accumulated depreciation	124,459,666	99,498,848
Accumulated depreciation	(14,108,154)	(9,386,811)
Net real estate assets	110,351,512	90,112,037
Other Assets	41,958,914	33,488,744
Assets	758,675,255	546,253,158
Liabilities
Accounts payable, accrued expenses and other liabilities	4,123,346	4,963,653
Dividends Payable, Current	7,617,390	6,446,076
Debt financing	345,359,000	257,274,000
Long-term Debt	76,707,834	57,087,320
Bond Purchase Commitment - Fair Market Value Adjustment - Liability		4,852,177
Liabilities	433,807,570	330,623,226
Partners' Capital
General Partner	578,238	16,671
Beneficial Unit Certificate holders	324,305,442	215,624,583
Unallocated deficit of Consolidated VIEs	0	0
Partners' Capital	324,883,680	215,641,254
Partners' Capital Attributable to Noncontrolling Interest	(15,995)	(11,322)
Total Capital	324,867,685	215,629,932
Total Liabilities and Partners' Capital	758,675,255	546,253,158
Consolidated VIEs [Member]
Assets [Abstract]
Cash and cash equivalents	35,772	25,976
Restricted cash	544,233	500,877
Interest receivable	0	0
Available-for-sale Securities, Fair Value Disclosure Held in Trust	0	0
Available-for-sale Securities	0	0
Public housing capital fund trusts, at fair value	0	0
Mortgage backed securities, at fair value	0	0
Real Estate Assets [Abstract]
Land and land improvements	1,836,400	1,836,400
Buildings and improvements	21,204,048	20,942,439
Real estate assets before accumulated depreciation	23,040,448	22,778,839
Accumulated depreciation	(10,583,646)	(9,741,942)
Net real estate assets	12,456,802	13,036,897
Other Assets	420,054	456,087
Assets	13,456,861	14,019,837	30,207,191
Liabilities
Accounts payable, accrued expenses and other liabilities	22,225,477	20,634,613
Dividends Payable, Current	0	0
Debt financing	0	0
Long-term Debt	14,731,000	14,897,000
Bond Purchase Commitment - Fair Market Value Adjustment - Liability		0
Liabilities	36,956,477	35,531,613
Partners' Capital
General Partner	0	0
Beneficial Unit Certificate holders	0	0
Unallocated deficit of Consolidated VIEs	(23,499,616)	(21,511,776)
Partners' Capital	(23,499,616)	(21,511,776)	(22,480,214)
Partners' Capital Attributable to Noncontrolling Interest	0	0
Total Capital	(23,499,616)	(21,511,776)
Total Liabilities and Partners' Capital	13,456,861	14,019,837
Consolidations, Eliminations for VIEs [Member]
Assets [Abstract]
Cash and cash equivalents	0	0
Restricted cash	0	0
Interest receivable	(670,342)	(1,939,360)
Available-for-sale Securities, Fair Value Disclosure Held in Trust	(16,145,116)	(14,514,063)
Available-for-sale Securities	0	0
Public housing capital fund trusts, at fair value	0	0
Mortgage backed securities, at fair value	0	0
Real Estate Assets [Abstract]
Land and land improvements	0	0
Buildings and improvements	0	0
Real estate assets before accumulated depreciation	0	0
Accumulated depreciation	0	0
Net real estate assets	0	0
Other Assets	(11,077,441)	(9,586,540)
Assets	(27,892,899)	(26,039,963)
Liabilities
Accounts payable, accrued expenses and other liabilities	(21,721,734)	(20,147,572)
Dividends Payable, Current	0	0
Debt financing	0	0
Long-term Debt	(14,731,000)	(14,897,000)
Bond Purchase Commitment - Fair Market Value Adjustment - Liability		0
Liabilities	(36,452,734)	(35,044,572)
Partners' Capital
General Partner	0	0
Beneficial Unit Certificate holders	6,151,675	7,948,729
Unallocated deficit of Consolidated VIEs	2,408,160	1,055,880
Partners' Capital	8,559,835	9,004,609
Partners' Capital Attributable to Noncontrolling Interest	0	0
Total Capital	8,559,835	9,004,609
Total Liabilities and Partners' Capital	$ (27,892,899)	$ (26,039,963)

This element represents the portion of the balance sheet assertion valued at fair value by the entity, which is held in trust, whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may by ued in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all sescuritized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

No definition available.