XML 29 R57.htm IDEA: XBRL DOCUMENT v2.4.1.9
Investments in Mortgage Revenue Bonds Certain Terms of Mortgage Revenue Bonds (Details) (USD $)
 12 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended 3 Months Ended 9 Months Ended 6 Months Ended
Dec. 31, 2014
Mar. 31, 2014
Jun. 30, 2014
Dec. 31, 2013
Dec. 31, 2012
Mar. 31, 2013
Sep. 30, 2014
Jun. 30, 2013
Sep. 30, 2013
Mar. 31, 2015
Available-for-sale Securities, at Par Value $ 409,506,066atax_AvailableForSaleSecuritiesAtParValue     $ 299,841,918atax_AvailableForSaleSecuritiesAtParValue            
Bruton Apts [Member]                    
Available-for-sale Security, Maturity Date at a point in time Aug. 01, 2054 [1]                  
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_BrutonAptsMember		 [1]                  
Available-for-sale Securities, at Par Value 18,145,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_BrutonAptsMember		 [1]                  
Decatur-Angle [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jan. 01, 2054 [1] Jan. 01, 2054                
Debt Instrument, Interest Rate, Stated Percentage 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_DecaturAngleMember		 [1] 5.80%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_DecaturAngleMember		                
Available-for-sale Securities, at Par Value 23,000,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_DecaturAngleMember		 [1]                  
Live 929 Apartments [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jul. 01, 2049 [1]   Jul. 01, 2049              
Debt Instrument, Interest Rate, Stated Percentage 5.78%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_Live929ApartmentsMember		 [1]   5.80%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_Live929ApartmentsMember		              
Available-for-sale Securities, at Par Value 40,245,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_Live929ApartmentsMember		 [1]                  
Pro Nova 2014-1 [Member]                    
Available-for-sale Security, Maturity Date at a point in time May 01, 2034                  
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_ProNova20141Member		                  
Available-for-sale Securities, at Par Value 10,000,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_ProNova20141Member		                  
Pro Nova 2014-2 [Member]                    
Available-for-sale Security, Maturity Date at a point in time May 01, 2025                  
Debt Instrument, Interest Rate, Stated Percentage 5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_ProNova20142Member		                  
Available-for-sale Securities, at Par Value 10,000,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_ProNova20142Member		                  
Arbors at Hickory Ridge [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2049 [2]     Dec. 01, 2049 [1]            
Debt Instrument, Interest Rate, Stated Percentage 6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_ArborsAtHickoryRidgeMember		 [2]     6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_ArborsAtHickoryRidgeMember		 [1]            
Available-for-sale Securities, at Par Value 11,450,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_ArborsAtHickoryRidgeMember		 [2]     11,450,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_ArborsAtHickoryRidgeMember		 [1]            
Ashley Square [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2025 [3]     Dec. 01, 2025 [3]            
Debt Instrument, Interest Rate, Stated Percentage 6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AshleySquareMember		 [3]     6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AshleySquareMember		 [3]            
Available-for-sale Securities, at Par Value 5,159,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AshleySquareMember		 [3]     5,212,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AshleySquareMember		 [3]            
Autumn Pines [Member]                    
Available-for-sale Security, Maturity Date at a point in time       Oct. 01, 2046 [1]            
Debt Instrument, Interest Rate, Stated Percentage       5.80%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AutumnPinesMember		 [1]            
Available-for-sale Securities, at Par Value       13,110,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AutumnPinesMember		 [1]            
Avistar Portfolio [Member]                    
Debt Instrument, Interest Rate, Stated Percentage     12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember		              
Bella Vista [Member]                    
Available-for-sale Security, Maturity Date at a point in time Apr. 01, 2046 [3]     Apr. 01, 2046 [3]            
Debt Instrument, Interest Rate, Stated Percentage 6.15%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_BellaVistaMember		 [3]     6.15%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_BellaVistaMember		 [3]            
Available-for-sale Securities, at Par Value 6,490,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_BellaVistaMember		 [3]     6,545,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_BellaVistaMember		 [3]            
Bridle Ridge [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jan. 01, 2043 [3]     Jan. 01, 2043 [3]            
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_BridleRidgeMember		 [3]     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_BridleRidgeMember		 [3]            
Available-for-sale Securities, at Par Value 7,655,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_BridleRidgeMember		 [3]     7,715,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_BridleRidgeMember		 [3]            
Brookstone [Member]                    
Available-for-sale Security, Maturity Date at a point in time May 01, 2040 [3]     May 01, 2040 [3]            
Debt Instrument, Interest Rate, Stated Percentage 5.45%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_BrookstoneMember		 [3]     5.45%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_BrookstoneMember		 [3]            
Available-for-sale Securities, at Par Value 9,256,001atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_BrookstoneMember		 [3]     9,338,603atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_BrookstoneMember		 [3]            
Copper Gate [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2029 [2]     Dec. 01, 2029            
Debt Instrument, Interest Rate, Stated Percentage 6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_CopperGateMember		 [2]     6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_CopperGateMember		            
Available-for-sale Securities, at Par Value 5,220,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_CopperGateMember		 [2]     5,220,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_CopperGateMember		            
Cross Creek [Member]                    
Available-for-sale Security, Maturity Date at a point in time Mar. 01, 2049                  
Debt Instrument, Interest Rate, Stated Percentage 6.15%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_CrossCreekMember		                  
Available-for-sale Securities, at Par Value 8,422,997atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_CrossCreekMember		                  
Greens of Pine Glen [Member]                    
Available-for-sale Security, Maturity Date at a point in time         Oct. 01, 2047          
Lake Forest [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2031 [3]     Dec. 01, 2031 [3]            
Debt Instrument, Interest Rate, Stated Percentage 6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_LakeForestMember		 [3]     6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_LakeForestMember		 [3]            
Available-for-sale Securities, at Par Value 8,886,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_LakeForestMember		 [3]     8,997,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_LakeForestMember		 [3]            
Runnymede [Member]                    
Available-for-sale Security, Maturity Date at a point in time Oct. 01, 2042 [3]     Oct. 01, 2042 [3]            
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RunnymedeMember		 [3]     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RunnymedeMember		 [3]            
Available-for-sale Securities, at Par Value 10,440,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RunnymedeMember		 [3]     10,525,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RunnymedeMember		 [3]            
Southpark [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2049 [3]     Dec. 01, 2049 [3]            
Debt Instrument, Interest Rate, Stated Percentage 6.13%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_SouthparkMember		 [3]     6.13%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_SouthparkMember		 [3]            
Available-for-sale Securities, at Par Value 13,680,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_SouthparkMember		 [3]     13,795,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_SouthparkMember		 [3]            
The Palms at Premier Park [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jan. 01, 2050 [2]     Jan. 01, 2050            
Debt Instrument, Interest Rate, Stated Percentage 6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_ThePalmsatPremierParkMember		 [2]     6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_ThePalmsatPremierParkMember		            
Available-for-sale Securities, at Par Value 20,152,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_ThePalmsatPremierParkMember		 [2]     20,152,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_ThePalmsatPremierParkMember		            
The Suites on Paseo [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2048 [1]     Dec. 01, 2048 [1]            
Debt Instrument, Interest Rate, Stated Percentage 6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_TheSuitesonPaseoMember		 [1]     6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_TheSuitesonPaseoMember		 [1]            
Available-for-sale Securities, at Par Value 35,450,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_TheSuitesonPaseoMember		 [1]     35,750,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_TheSuitesonPaseoMember		 [1]            
Vantage at Judson [Member]                    
Available-for-sale Security, Maturity Date at a point in time Feb. 01, 2053     Feb. 01, 2053 Feb. 01, 2053          
Debt Instrument, Interest Rate, Stated Percentage 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_VantageAtJudsonMember		     9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_VantageAtJudsonMember		 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_VantageAtJudsonMember		          
Available-for-sale Securities, at Par Value 6,049,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_VantageAtJudsonMember		     6,049,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_VantageAtJudsonMember		            
Vantage at Harlingen [Member]                    
Available-for-sale Security, Maturity Date at a point in time Sep. 01, 2053     Oct. 01, 2053            
Debt Instrument, Interest Rate, Stated Percentage 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_VantageatHarlingenMember		     9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_VantageatHarlingenMember		            
Available-for-sale Securities, at Par Value 6,692,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_VantageatHarlingenMember		     6,692,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_VantageatHarlingenMember		            
Woodland Park [Member]                    
Debt Instrument, Interest Rate, Stated Percentage                 2.80%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_WoodlandParkMember		  
Woodlynn Village [Member]                    
Available-for-sale Security, Maturity Date at a point in time Nov. 01, 2042 [3]     Nov. 01, 2042 [3]            
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_WoodlynnVillageMember		 [3]     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_WoodlynnVillageMember		 [3]            
Available-for-sale Securities, at Par Value 4,390,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_WoodlynnVillageMember		 [3]     4,426,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_WoodlynnVillageMember		 [3]            
Series A [Member] | Glenview Apts [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2031                  
Debt Instrument, Interest Rate, Stated Percentage 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_GlenviewAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		                  
Available-for-sale Securities, at Par Value 4,670,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_GlenviewAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		                  
Series A [Member] | Harden Ranch [Member]                    
Available-for-sale Security, Maturity Date at a point in time Mar. 01, 2030 [2] Mar. 01, 2030                
Debt Instrument, Interest Rate, Stated Percentage 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_HardenRanchMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2] 5.80%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_HardenRanchMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		                
Available-for-sale Securities, at Par Value 6,960,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_HardenRanchMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]                  
Series A [Member] | Heritage Square [Member]                    
Available-for-sale Security, Maturity Date at a point in time Sep. 01, 2051                  
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_HeritageSquareMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		           6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_HeritageSquareMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		      
Available-for-sale Securities, at Par Value 11,185,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_HeritageSquareMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		                  
Series A [Member] | Montclair Apts [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2031                  
Debt Instrument, Interest Rate, Stated Percentage 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_MontclairAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		                  
Available-for-sale Securities, at Par Value 2,530,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_MontclairAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		                  
Series A [Member] | Renaissance Gateway [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jun. 01, 2050                  
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		             6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		    
Available-for-sale Securities, at Par Value 8,550,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		     3,900,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		     4,700,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 8,600,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		    
Series A [Member] | Santa Fe Apts [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2031                  
Debt Instrument, Interest Rate, Stated Percentage 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_SantaFeAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		                  
Available-for-sale Securities, at Par Value 3,065,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_SantaFeAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		                  
Series A [Member] | Avistar on the Boulevard [Member]                    
Available-for-sale Security, Maturity Date at a point in time Mar. 01, 2050 [2]     Mar. 01, 2050 [1]            
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarOnBoulevardMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarOnBoulevardMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Available-for-sale Securities, at Par Value 16,525,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarOnBoulevardMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     13,760,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarOnBoulevardMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Series A [Member] | Avistar at Chase Hill [Member]                    
Available-for-sale Security, Maturity Date at a point in time Mar. 01, 2050 [2]     Mar. 01, 2050 [1]            
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarAtChaseHillMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarAtChaseHillMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Available-for-sale Securities, at Par Value 10,000,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarAtChaseHillMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     8,960,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarAtChaseHillMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Series A [Member] | Avistar at the Crest [Member]                    
Available-for-sale Security, Maturity Date at a point in time Mar. 01, 2050 [2]     Mar. 01, 2050 [1]            
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarAtCrestMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarAtCrestMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Available-for-sale Securities, at Par Value 9,700,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarAtCrestMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     8,759,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarAtCrestMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Series A [Member] | Avistar Portfolio [Member]                    
Available-for-sale Security, Maturity Date at a point in time           Mar. 01, 2050 Mar. 01, 2050      
Debt Instrument, Interest Rate, Stated Percentage           6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		      
Series A [Member] | Avistar at the Oaks [Member]                    
Available-for-sale Security, Maturity Date at a point in time Aug. 01, 2050 [2]     Aug. 01, 2050 [1]            
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarattheOaksMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarattheOaksMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Available-for-sale Securities, at Par Value 7,800,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarattheOaksMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     5,878,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarattheOaksMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Series A [Member] | Avistar in 09 [Member]                    
Available-for-sale Security, Maturity Date at a point in time Aug. 01, 2050 [2]     Aug. 01, 2050 [1]            
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_Avistarin09Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_Avistarin09Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Available-for-sale Securities, at Par Value 6,735,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_Avistarin09Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     5,482,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_Avistarin09Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Series A [Member] | Avistar on the Hills [Member]                    
Available-for-sale Security, Maturity Date at a point in time Aug. 01, 2050 [2]     Aug. 01, 2050 [1]            
Debt Instrument, Interest Rate, Stated Percentage 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarontheHillsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarontheHillsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Available-for-sale Securities, at Par Value 5,389,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarontheHillsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     3,091,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarontheHillsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Series A [Member] | Avistar Portolio-2 [Member]                    
Available-for-sale Security, Maturity Date at a point in time     Aug. 01, 2050              
Debt Instrument, Interest Rate, Stated Percentage     6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		              
Series A [Member] | Cross Creek [Member]                    
Available-for-sale Security, Maturity Date at a point in time       Mar. 01, 2049 [3]            
Debt Instrument, Interest Rate, Stated Percentage       6.15%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_CrossCreekMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [3]            
Available-for-sale Securities, at Par Value       8,497,933atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_CrossCreekMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [3]            
Series A [Member] | Greens of Pine Glen [Member]                    
Available-for-sale Security, Maturity Date at a point in time Oct. 01, 2047 [2]     Oct. 01, 2047 [1]            
Debt Instrument, Interest Rate, Stated Percentage 6.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     6.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1] 6.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		          
Available-for-sale Securities, at Par Value 8,366,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     8,437,501atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1] 8,515,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		          
Series A [Member] | Ohio Properties [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jun. 01, 2050 [3]     Jun. 01, 2050 [1]            
Debt Instrument, Interest Rate, Stated Percentage 7.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_OhioPropertiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [3]     7.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_OhioPropertiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Available-for-sale Securities, at Par Value 14,407,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_OhioPropertiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [3]     14,498,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_OhioPropertiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [1]            
Series A [Member] | Rennaisance [Member]                    
Available-for-sale Security, Maturity Date at a point in time       Jun. 01, 2050            
Debt Instrument, Interest Rate, Stated Percentage       6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RennaisanceMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		            
Available-for-sale Securities, at Par Value       3,850,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RennaisanceMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		            
Series A [Member] | Tyler Park Apartments [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jan. 01, 2030 [2]     Jan. 01, 2030            
Debt Instrument, Interest Rate, Stated Percentage 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_TylerParkApartmentsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_TylerParkApartmentsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		            
Available-for-sale Securities, at Par Value 6,075,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_TylerParkApartmentsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     6,075,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_TylerParkApartmentsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		            
Series A [Member] | Lost Creek [Member]                    
Available-for-sale Security, Maturity Date at a point in time       Jun. 01, 2041            
Debt Instrument, Interest Rate, Stated Percentage       6.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_LostCreekMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		            
Available-for-sale Securities, at Par Value       18,090,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_LostCreekMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		            
Series A [Member] | Westside Village Market [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jan. 01, 2030 [2]     Jan. 01, 2030            
Debt Instrument, Interest Rate, Stated Percentage 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_WestsideVillageMarketMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_WestsideVillageMarketMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		            
Available-for-sale Securities, at Par Value 3,970,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_WestsideVillageMarketMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		 [2]     3,970,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_WestsideVillageMarketMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesAMember		            
Series C [Member] | Renaissance Gateway [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jun. 01, 2015             Jun. 01, 2015    
Debt Instrument, Interest Rate, Stated Percentage 12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		             12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		    
Available-for-sale Securities, at Par Value 2,875,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		             2,900,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		    
Series C [Member] | Avistar Portfolio [Member]                    
Available-for-sale Security, Maturity Date at a point in time       Apr. 01, 2050   Apr. 01, 2050 Apr. 01, 2050      
Debt Instrument, Interest Rate, Stated Percentage       9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		   9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		      
Available-for-sale Securities, at Par Value       804,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		   804,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		 804,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		      
Series C [Member] | Avistar Portolio-2 [Member]                    
Available-for-sale Security, Maturity Date at a point in time     Sep. 01, 2050 Sep. 01, 2050            
Debt Instrument, Interest Rate, Stated Percentage     9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		            
Available-for-sale Securities, at Par Value     831,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		 831,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		            
Series C [Member] | Rennaisance [Member]                    
Available-for-sale Security, Maturity Date at a point in time       Jun. 01, 2015            
Debt Instrument, Interest Rate, Stated Percentage       12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RennaisanceMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		            
Available-for-sale Securities, at Par Value       2,875,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RennaisanceMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		            
Series C [Member] | Vantage at Judson [Member]                    
Available-for-sale Securities, at Par Value 6,000,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_VantageAtJudsonMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		       6,000,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_VantageAtJudsonMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		          
Series C [Member] | Vantage at Harlingen [Member]                    
Debt Instrument, Interest Rate, Stated Percentage       9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_VantageatHarlingenMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		            
Available-for-sale Securities, at Par Value       6,700,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_VantageatHarlingenMember
/ invest_InvestmentSecuritiesSeriesAxis
= atax_SeriesCMember		            
Series B [Member] | Glenview Apts [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2016                  
Debt Instrument, Interest Rate, Stated Percentage 5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_GlenviewAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Available-for-sale Securities, at Par Value 2,053,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_GlenviewAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Series B [Member] | Harden Ranch [Member]                    
Available-for-sale Security, Maturity Date at a point in time Mar. 01, 2016 Mar. 01, 2016                
Debt Instrument, Interest Rate, Stated Percentage 5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_HardenRanchMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		           5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_HardenRanchMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     8.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_HardenRanchMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember
Available-for-sale Securities, at Par Value 2,340,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_HardenRanchMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Series B [Member] | Heritage Square [Member]                    
Available-for-sale Security, Maturity Date at a point in time Oct. 01, 2051           Oct. 01, 2051      
Debt Instrument, Interest Rate, Stated Percentage 12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_HeritageSquareMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		           12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_HeritageSquareMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		      
Available-for-sale Securities, at Par Value 520,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_HeritageSquareMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Series B [Member] | Montclair Apts [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2016                  
Debt Instrument, Interest Rate, Stated Percentage 5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_MontclairAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Available-for-sale Securities, at Par Value 928,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_MontclairAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Series B [Member] | Renaissance Gateway [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jun. 01, 2050                  
Debt Instrument, Interest Rate, Stated Percentage 12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		             12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		    
Available-for-sale Securities, at Par Value 1,250,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     1,300,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RenaissanceGatewayMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Series B [Member] | Santa Fe Apts [Member]                    
Available-for-sale Security, Maturity Date at a point in time Dec. 01, 2016                  
Debt Instrument, Interest Rate, Stated Percentage 5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_SantaFeAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Available-for-sale Securities, at Par Value 1,671,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_SantaFeAptsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Series B [Member] | Avistar Portfolio [Member]                    
Available-for-sale Security, Maturity Date at a point in time Apr. 01, 2050     Apr. 01, 2050   Apr. 01, 2050 Apr. 01, 2050      
Debt Instrument, Interest Rate, Stated Percentage 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		   9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		      
Available-for-sale Securities, at Par Value 2,175,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     6,921,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarPortfolioMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Series B [Member] | Avistar Portolio-2 [Member]                    
Available-for-sale Security, Maturity Date at a point in time Sep. 01, 2050   Sep. 01, 2050 Sep. 01, 2050 [1]            
Debt Instrument, Interest Rate, Stated Percentage 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		   9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		 [1]            
Available-for-sale Securities, at Par Value 1,011,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     6,484,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_AvistarPortolio2Member
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		 [1]            
Series B [Member] | Greens of Pine Glen [Member]                    
Available-for-sale Security, Maturity Date at a point in time Oct. 01, 2047     Oct. 01, 2047 [1]            
Debt Instrument, Interest Rate, Stated Percentage 9.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		 [1] 12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		          
Available-for-sale Securities, at Par Value 945,638atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     948,291atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		 [1] 950,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_GreensOfPineGlenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		          
Series B [Member] | Ohio Properties [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jun. 01, 2050     Jun. 01, 2050            
Debt Instrument, Interest Rate, Stated Percentage 10.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_OhioPropertiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     10.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_OhioPropertiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Available-for-sale Securities, at Par Value 3,573,430atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_OhioPropertiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     3,583,590atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_OhioPropertiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Series B [Member] | Rennaisance [Member]                    
Available-for-sale Security, Maturity Date at a point in time       Jun. 01, 2050            
Debt Instrument, Interest Rate, Stated Percentage       12.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_RennaisanceMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Available-for-sale Securities, at Par Value       1,250,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_RennaisanceMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Series B [Member] | Tyler Park Apartments [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jan. 01, 2016     Jan. 01, 2016            
Debt Instrument, Interest Rate, Stated Percentage 5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_TylerParkApartmentsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_TylerParkApartmentsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Available-for-sale Securities, at Par Value 2,025,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_TylerParkApartmentsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     2,025,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_TylerParkApartmentsMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Series B [Member] | Vantage at Judson [Member]                    
Debt Instrument, Interest Rate, Stated Percentage 0.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_VantageAtJudsonMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Available-for-sale Securities, at Par Value 26,700,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_VantageAtJudsonMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		                  
Series B [Member] | Vantage at Harlingen [Member]                    
Debt Instrument, Interest Rate, Stated Percentage       6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_VantageatHarlingenMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Series B [Member] | Westside Village Market [Member]                    
Available-for-sale Security, Maturity Date at a point in time Jan. 01, 2016     Jan. 01, 2016            
Debt Instrument, Interest Rate, Stated Percentage 5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_WestsideVillageMarketMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     5.50%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ dei_EntityByLocationAxis
= atax_WestsideVillageMarketMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
Available-for-sale Securities, at Par Value $ 1,430,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_WestsideVillageMarketMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		     $ 1,430,000atax_AvailableForSaleSecuritiesAtParValue
/ dei_EntityByLocationAxis
= atax_WestsideVillageMarketMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_SeriesBMember		            
[1] Bond held by Deutsche Bank in a secured financing transaction, Note 11
[2] (3) Bonds owned by ATAX TEBS II, LLC, Note 11
[3] Bonds owned by ATAX TEBS I, LLC, Note 11