Investments in Mortgage Revenue Bonds Investments in Mortgage Revenue Bonds(Details) - USD ($)		Sep. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust		$ 454,875,266		$ 338,861,752
Cost adjusted for pay-downs		25,193,081		65,538,068
Unrealized Gain, held in trust		44,322,296		39,561,340
Unrealized Gain		3,080,857		5,082,559
Unrealized Loss, held in trust		0		0
Unrealized Loss		(25,958)		(19,582)
Estimated Fair Value, held in trust		499,197,562		378,423,092
Estimated Fair Value		28,247,980		70,601,045
Arbors at Hickory Ridge [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	11,566,976		11,570,933
Unrealized Gain, held in trust	[1]	1,537,005		1,792,303
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	13,103,981		13,363,236
Ashley Square [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	5,114,000		5,159,000
Unrealized Gain, held in trust	[2]	458,262		486,559
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	5,572,262		5,645,559
Avistar on the Hills [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]			5,389,000
Unrealized Gain, held in trust	[1]			743,520
Unrealized Loss, held in trust	[1]			0
Estimated Fair Value, held in trust	[1]			6,132,520
Bella Vista [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	6,430,000		6,490,000
Unrealized Gain, held in trust	[2]	614,644		625,571
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	7,044,644		7,115,571
Bridle Ridge [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	7,595,000		7,655,000
Unrealized Gain, held in trust	[2]	645,575		659,249
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	8,240,575		8,314,249
Brookstone [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	7,469,252		7,468,888
Unrealized Gain, held in trust	[2]	1,663,402		1,360,589
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	9,132,654		8,829,477
Bruton Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[3]			18,145,000
Unrealized Gain, held in trust	[3]			1,455,955
Unrealized Loss, held in trust	[3]			0
Estimated Fair Value, held in trust	[3]			19,600,955
Bruton Apartments [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[3]	18,145,000
Unrealized Gain, held in trust	[3]	1,503,516
Unrealized Loss, held in trust	[3]	0
Estimated Fair Value, held in trust	[3]	19,648,516
Glenview Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				6,723,000
Unrealized Gain				0
Unrealized Loss				0
Estimated Fair Value				6,723,000
Copper Gate [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	5,220,000		5,220,000
Unrealized Gain, held in trust	[1]	544,237		563,656
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	5,764,237		5,783,656
Cross Creek [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	6,095,463		6,074,817
Unrealized Gain, held in trust	[2]	2,807,730		2,542,262
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	8,903,193		8,617,079
Decatur-Angle [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[3]	23,000,000		23,000,000
Unrealized Gain, held in trust	[3]	1,094,952		919,540
Unrealized Loss, held in trust	[3]	0		0
Estimated Fair Value, held in trust	[3]	24,094,952		23,919,540
Heritage Square [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				11,705,000
Unrealized Gain				1,109,125
Unrealized Loss				0
Estimated Fair Value				12,814,125
Montclair Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				3,458,000
Unrealized Gain				0
Unrealized Loss				0
Estimated Fair Value				3,458,000
Lake Forest [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	8,796,000		8,886,000
Unrealized Gain, held in trust	[2]	1,055,791		1,003,614
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	9,851,791		9,889,614
Live 929 Apartments [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[3]	40,822,598		40,895,739
Unrealized Gain, held in trust	[3]	4,262,624		3,797,745
Unrealized Loss, held in trust	[3]	0		0
Estimated Fair Value, held in trust	[3]	45,085,222		44,693,484
Pro Nova [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[3]	19,382,099		20,095,169
Unrealized Gain, held in trust	[3]	771,618		1,043,431
Unrealized Loss, held in trust	[3]	0		0
Estimated Fair Value, held in trust	[3]	20,153,717		21,138,600
Rennaisance [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				12,675,000
Unrealized Gain				1,055,807
Unrealized Loss				0
Estimated Fair Value				13,730,807
Runnymede [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	10,395,000		10,440,000
Unrealized Gain, held in trust	[2]	1,199,375		1,385,910
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	11,594,375		11,825,910
Southpark [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	11,900,457		11,842,206
Unrealized Gain, held in trust	[2]	3,670,256		3,743,692
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	15,570,713		15,585,898
The Palms at Premier Park [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	20,043,237		20,152,000
Unrealized Gain, held in trust	[1]	2,112,835		2,680,619
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	22,156,072		22,832,619
The Suites on Paseo [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[3]			35,450,000
Unrealized Gain, held in trust	[3]			3,193,691
Unrealized Loss, held in trust	[3]			0
Estimated Fair Value, held in trust	[3]			38,643,691
Vantage at Harlingen [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				6,692,000
Unrealized Gain				707,813
Unrealized Loss				0
Estimated Fair Value				7,399,813
Vantage at Judson [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				6,049,000
Unrealized Gain				717,230
Unrealized Loss				0
Estimated Fair Value				6,766,230
Woodlynn Village [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	4,371,000		4,390,000
Unrealized Gain, held in trust	[2]	273,712		376,706
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	4,644,712		4,766,706
Santa Fe Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				4,736,000
Unrealized Gain				0
Unrealized Loss				0
Estimated Fair Value				4,736,000
Seasons at Simi Valley [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		6,320,000
Unrealized Gain		219,709
Unrealized Loss		0
Estimated Fair Value		6,539,709
Series A [Member] | Avistar at Chase Hill [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	9,957,357		10,000,000
Unrealized Gain, held in trust	[1]	1,140,898		1,196,800
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	11,098,255		11,196,800
Series A [Member] | Avistar at the Crest [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	9,658,636		9,700,000
Unrealized Gain, held in trust	[1]	1,106,671		1,419,692
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	10,765,307		11,119,692
Series A [Member] | Avistar at the Oaks [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	7,794,525		7,800,000
Unrealized Gain, held in trust	[1]	954,785		869,622
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	8,749,310		8,669,622
Series A [Member] | Avistar in 09 [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	6,730,273		6,735,000
Unrealized Gain, held in trust	[1]	730,354		750,885
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	7,460,627		7,485,885
Series A [Member] | Avistar on the Boulevard [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	16,454,530		16,525,000
Unrealized Gain, held in trust	[1]	1,548,219		2,418,599
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	18,002,749		18,943,599
Series A [Member] | Avistar on the Hills [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	5,385,217
Unrealized Gain, held in trust	[1]	584,391
Unrealized Loss, held in trust	[1]	0
Estimated Fair Value, held in trust	[1]	5,969,608
Series A [Member] | Concord at Gulfgate [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[3]	17,060,000
Cost adjusted for pay-downs		17,100,000
Unrealized Gain, held in trust	[3]	862,126
Unrealized Loss, held in trust	[3]	0
Estimated Fair Value, held in trust	[3]	17,922,126
Series A [Member] | Concord at Little York [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[3]	12,480,000
Cost adjusted for pay-downs		12,500,000
Unrealized Gain, held in trust	[3]	630,743
Unrealized Loss, held in trust	[3]	0
Estimated Fair Value, held in trust	[3]	13,110,743
Series A [Member] | Concord at Williamcrest [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[3]	18,020,000
Cost adjusted for pay-downs		18,000,000
Unrealized Gain, held in trust	[3]	910,663
Unrealized Loss, held in trust	[3]	0
Estimated Fair Value, held in trust	[3]	18,930,663
Series A [Member] | Glenview Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[4]	4,670,000
Unrealized Gain, held in trust	[4]	140,594
Unrealized Loss, held in trust	[4]	0
Estimated Fair Value, held in trust	[4]	4,810,594
Series A [Member] | Greens of Pine Glen [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	8,312,000		8,366,000
Unrealized Gain, held in trust	[1]	983,623		1,005,119
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	9,295,623		9,371,119
Series A [Member] | Heritage Square [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[4]	11,185,000
Unrealized Gain, held in trust	[4]	67,782
Unrealized Loss, held in trust	[4]	0
Estimated Fair Value, held in trust	[4]	11,252,782
Series A [Member] | Montclair Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[4]	2,530,000
Unrealized Gain, held in trust	[4]	76,168
Unrealized Loss, held in trust	[4]	0
Estimated Fair Value, held in trust	[4]	2,606,168
Series A [Member] | Harden Ranch [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	6,960,000		6,960,000
Unrealized Gain, held in trust	[1]	571,277		511,421
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	7,531,277		7,471,421
Series A [Member] | Ohio Properties [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[2]	14,335,000		14,407,000
Unrealized Gain, held in trust	[2]	2,604,402		2,444,034
Unrealized Loss, held in trust	[2]	0		0
Estimated Fair Value, held in trust	[2]	16,939,402		16,851,034
Series A [Member] | Renaissance Gateway [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[4]	11,475,663
Cost adjusted for pay-downs		11,500,000	$ 8,500,000
Unrealized Gain, held in trust	[4]	1,007,469
Unrealized Loss, held in trust	[4]	0
Estimated Fair Value, held in trust	[4]	12,483,132
Series A [Member] | Perrin Square [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[4]	13,300,000
Cost adjusted for pay-downs		13,300,000
Unrealized Gain, held in trust	[4]	81,808
Unrealized Loss, held in trust	[4]	0
Estimated Fair Value, held in trust	[4]	13,381,808
Series A [Member] | Silver Moon [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[4]	7,995,983
Cost adjusted for pay-downs		8,000,000
Unrealized Gain, held in trust	[4]	1,064,256
Unrealized Loss, held in trust	[4]	0
Estimated Fair Value, held in trust	[4]	9,060,239
Series A [Member] | Tyler Park Apartments [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	6,075,000		6,075,000
Unrealized Gain, held in trust	[1]	403,195		345,060
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	6,478,195		6,420,060
Series A [Member] | Westside Village Market [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[1]	3,970,000		3,970,000
Unrealized Gain, held in trust	[1]	263,487		225,496
Unrealized Loss, held in trust	[1]	0		0
Estimated Fair Value, held in trust	[1]	4,233,487		4,195,496
Series A [Member] | Santa Fe Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[4]	3,065,000
Unrealized Gain, held in trust	[4]	139,805
Unrealized Loss, held in trust	[4]	0
Estimated Fair Value, held in trust	[4]	3,204,805
Series B [Member] | Avistar at Chase Hill [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		963,011		965,000
Unrealized Gain		94,072		144,769
Unrealized Loss		0		0
Estimated Fair Value		1,057,083		1,109,769
Series B [Member] | Avistar at the Crest [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		757,434		759,000
Unrealized Gain		73,993		124,286
Unrealized Loss		0		0
Estimated Fair Value		831,427		883,286
Series B [Member] | Avistar at the Oaks [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		553,813		554,000
Unrealized Gain		54,379		54,325
Unrealized Loss		0		0
Estimated Fair Value		608,192		608,325
Series B [Member] | Avistar in 09 [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		456,846		457,000
Unrealized Gain		44,858		50,608
Unrealized Loss		0		0
Estimated Fair Value		501,704		507,608
Series B [Member] | Avistar on the Boulevard [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		450,070		451,000
Unrealized Gain		43,966		73,851
Unrealized Loss		0		0
Estimated Fair Value		494,036		524,851
Series B [Member] | Concord at Gulfgate [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		2,125,000
Unrealized Gain		613,794
Unrealized Loss		0
Estimated Fair Value		2,738,794
Series B [Member] | Concord at Little York [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		960,000
Unrealized Gain		252,621
Unrealized Loss		0
Estimated Fair Value		1,212,621
Series B [Member] | Concord at Williamcrest [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		2,800,000
Unrealized Gain		572,669
Unrealized Loss		0
Estimated Fair Value		3,372,669
Series B [Member] | Glenview Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		2,053,000
Unrealized Gain		0
Unrealized Loss		(12,729)
Estimated Fair Value		2,040,271
Series B [Member] | Greens of Pine Glen [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		943,847		945,638
Unrealized Gain		253,494		376,203
Unrealized Loss		0		0
Estimated Fair Value		1,197,341		1,321,841
Series B [Member] | Heritage Square [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		520,000
Unrealized Gain		124,101
Unrealized Loss		0
Estimated Fair Value		644,101
Series B [Member] | Montclair Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		928,000
Unrealized Gain		0
Unrealized Loss		(4,724)
Estimated Fair Value		923,276
Series B [Member] | Harden Ranch [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				2,340,000
Unrealized Gain				0
Unrealized Loss				(1,501)
Estimated Fair Value				2,338,499
Series B [Member] | Ohio Properties [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		3,566,060		3,573,430
Unrealized Gain		703,159		668,542
Unrealized Loss		0		0
Estimated Fair Value		4,269,219		4,241,972
Series B [Member] | Renaissance Gateway [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs			$ 1,300,000
Series B [Member] | Perrin Square [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		125,000
Unrealized Gain		30,042
Unrealized Loss		0
Estimated Fair Value		155,042
Series B [Member] | Silver Moon [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		500,000
Series B [Member] | Tyler Park Apartments [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				2,025,000
Unrealized Gain				0
Unrealized Loss				(17,395)
Estimated Fair Value				2,007,605
Series B [Member] | Vantage at Harlingen [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[4]	24,575,000
Cost adjusted for pay-downs		24,600,000
Unrealized Gain, held in trust	[4]	1,605,115
Unrealized Loss, held in trust	[4]	0
Estimated Fair Value, held in trust	[4]	26,180,115
Series B [Member] | Vantage at Judson [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs, held in trust	[4]	26,540,000
Cost adjusted for pay-downs		26,500,000
Unrealized Gain, held in trust	[4]	2,628,931
Unrealized Loss, held in trust	[4]	0
Estimated Fair Value, held in trust	[4]	29,168,931
Series B [Member] | Westside Village Market [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs				1,430,000
Unrealized Gain				0
Unrealized Loss				(686)
Estimated Fair Value				$ 1,429,314
Series B [Member] | Santa Fe Apts [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost adjusted for pay-downs		1,671,000
Unrealized Gain		0
Unrealized Loss		(8,505)
Estimated Fair Value		$ 1,662,495

[1] Mortgage revenue bonds owned by ATAX TEBS II, LLC, see Note 11(4) Mortgage revenue bonds owned by ATAX TEBS III, LLC, see Note 11

[2] Mortgage revenue bonds owned by ATAX TEBS I, LLC, see Note 11

[3] Mortgage revenue bonds held by Deutsche Bank in a secured financing transaction, see Note 11

[4] Mortgage revenue bonds owned by ATAX TEBS III, LLC, see Note 11