Investments in Mortgage Revenue Bonds - Schedule of investments in MRBs (Details) - USD ($)		Sep. 30, 2019		Dec. 31, 2018
Mortgage Revenue Bonds Held In Trust [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		$ 650,161,253		$ 586,445,474
Cumulative Unrealized Gain		97,492,353		58,813,399
Cumulative Unrealized Loss		(496,219)
Estimated Fair Value		747,157,387		645,258,873
Mortgage Revenue Bonds Held In Trust [Member] | Courtyard [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	10,168,651		10,230,000
Cumulative Unrealized Gain	[1]	1,696,441		954,573
Estimated Fair Value	[1]	11,865,092		11,184,573
Mortgage Revenue Bonds Held In Trust [Member] | Glenview Apartments [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[2]	4,546,210		4,581,930
Cumulative Unrealized Gain	[2]	767,387		524,024
Estimated Fair Value	[2]	5,313,597		5,105,954
Mortgage Revenue Bonds Held In Trust [Member] | Harmony Court Bakersfield [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	3,707,631		3,730,000
Cumulative Unrealized Gain	[1]	582,453		312,844
Estimated Fair Value	[1]	4,290,084		4,042,844
Mortgage Revenue Bonds Held In Trust [Member] | Harmony Terrace [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	6,863,296		6,900,000
Cumulative Unrealized Gain	[1]	1,185,795		647,686
Estimated Fair Value	[1]	8,049,091		7,547,686
Mortgage Revenue Bonds Held In Trust [Member] | Harden Ranch [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	6,719,931		6,775,508
Cumulative Unrealized Gain	[3]	1,207,559		1,007,557
Estimated Fair Value	[3]	7,927,490		7,783,065
Mortgage Revenue Bonds Held In Trust [Member] | Las Palmas II [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	1,682,524		1,692,774
Cumulative Unrealized Gain	[1]	278,924		141,187
Estimated Fair Value	[1]	1,961,448		1,833,961
Mortgage Revenue Bonds Held In Trust [Member] | Montclair Apartments [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[2]	2,462,936		2,482,288
Cumulative Unrealized Gain	[2]	415,737		246,752
Estimated Fair Value	[2]	2,878,673		2,729,040
Mortgage Revenue Bonds Held In Trust [Member] | Montecito at Williams Ranch Apartments [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		7,690,000	[4]	7,690,000	[5]
Cumulative Unrealized Gain		1,651,838	[4]	973,133	[5]
Estimated Fair Value		9,341,838	[4]	8,663,133	[5]
Mortgage Revenue Bonds Held In Trust [Member] | San Vicente [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	3,469,276		3,490,410
Cumulative Unrealized Gain	[1]	558,315		291,121
Estimated Fair Value	[1]	4,027,591		3,781,531
Mortgage Revenue Bonds Held In Trust [Member] | Santa Fe Apartments [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[2]	2,983,755		3,007,198
Cumulative Unrealized Gain	[2]	548,485		401,203
Estimated Fair Value	[2]	3,532,240		3,408,401
Mortgage Revenue Bonds Held In Trust [Member] | Seasons at Simi Valley [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	4,293,474		4,325,536
Cumulative Unrealized Gain	[1]	912,975		655,326
Estimated Fair Value	[1]	5,206,449		4,980,862
Mortgage Revenue Bonds Held In Trust [Member] | Seasons Lakewood [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	7,310,902		7,350,000
Cumulative Unrealized Gain	[1]	1,191,125		654,929
Estimated Fair Value	[1]	8,502,027		8,004,929
Mortgage Revenue Bonds Held In Trust [Member] | Seasons San Juan Capistrano [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	12,309,171		12,375,000
Cumulative Unrealized Gain	[1]	2,005,465		1,102,687
Estimated Fair Value	[1]	14,314,636		13,477,687
Mortgage Revenue Bonds Held In Trust [Member] | Summerhill [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	6,384,482		6,423,000
Cumulative Unrealized Gain	[1]	972,132		508,639
Estimated Fair Value	[1]	7,356,614		6,931,639
Mortgage Revenue Bonds Held In Trust [Member] | Sycamore Walk [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	3,568,952		3,598,006
Cumulative Unrealized Gain	[1]	590,916		363,405
Estimated Fair Value	[1]	4,159,868		3,961,411
Mortgage Revenue Bonds Held In Trust [Member] | The Village at Madera [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	3,066,499		3,085,000
Cumulative Unrealized Gain	[1]	481,734		229,934
Estimated Fair Value	[1]	3,548,233		3,314,934
Mortgage Revenue Bonds Held In Trust [Member] | Tyler Park Townhomes [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	5,854,394		5,903,368
Cumulative Unrealized Gain	[3]	859,781		731,073
Estimated Fair Value	[3]	6,714,175		6,634,441
Mortgage Revenue Bonds Held In Trust [Member] | Vineyard Gardens | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		3,995,000	[4]	3,995,000	[5]
Cumulative Unrealized Gain		852,151	[4]	534,351	[5]
Estimated Fair Value		4,847,151	[4]	4,529,351	[5]
Mortgage Revenue Bonds Held In Trust [Member] | Westside Village Market [Member] | Series A [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	3,825,835		3,857,839
Cumulative Unrealized Gain	[3]	601,208		483,436
Estimated Fair Value	[3]	4,427,043		4,341,275
Mortgage Revenue Bonds Held In Trust [Member] | Brookstone [Member] | IL [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[6]	7,413,743		7,432,076
Cumulative Unrealized Gain	[6]	2,191,618		1,956,010
Estimated Fair Value	[6]	9,605,361		9,388,086
Mortgage Revenue Bonds Held In Trust [Member] | Copper Gate Apartments [Member] | IN [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	5,055,000		5,055,000
Cumulative Unrealized Gain	[3]	710,986		643,012
Estimated Fair Value	[3]	5,765,986		5,698,012
Mortgage Revenue Bonds Held In Trust [Member] | Renaissance [Member] | Series A [Member] | LA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[2]	11,032,412		11,123,800
Cumulative Unrealized Gain	[2]	1,899,144		1,383,680
Estimated Fair Value	[2]	12,931,556		12,507,480
Mortgage Revenue Bonds Held In Trust [Member] | Live 929 Apartments [Member] | MD [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		40,055,592	[4],[7]	40,240,405	[5]
Cumulative Unrealized Gain	[5]			2,873,978
Cumulative Unrealized Loss	[4],[7]	(149,095)
Estimated Fair Value		39,906,497	[4],[7]	43,114,383	[5]
Mortgage Revenue Bonds Held In Trust [Member] | Woodlynn Village [Member] | MN [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[6]	4,197,000		4,221,000
Cumulative Unrealized Gain	[6]	10,509		34,155
Estimated Fair Value	[6]	4,207,509		4,255,155
Mortgage Revenue Bonds Held In Trust [Member] | Gateway Village [Member] | NC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[5]	2,600,000
Cumulative Unrealized Gain	[5]	289,170
Estimated Fair Value	[5]	2,889,170
Mortgage Revenue Bonds Held In Trust [Member] | Greens Property [Member] | Series A [Member] | NC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	7,960,000		8,032,000
Cumulative Unrealized Gain	[3]	844,249		818,686
Estimated Fair Value	[3]	8,804,249		8,850,686
Mortgage Revenue Bonds Held In Trust [Member] | Lynnhaven Apartments [Member] | NC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[5]	3,450,000
Cumulative Unrealized Gain	[5]	383,707
Estimated Fair Value	[5]	3,833,707
Mortgage Revenue Bonds Held In Trust [Member] | Silver Moon [Member] | Series A [Member] | NM [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[2]	7,777,580		7,822,610
Cumulative Unrealized Gain	[2]	1,447,981		778,940
Estimated Fair Value	[2]	9,225,561		8,601,550
Mortgage Revenue Bonds Held In Trust [Member] | Village At Avalon [Member] | Series A [Member] | NM [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[8]	16,329,272
Cumulative Unrealized Gain	[8]	3,275,151
Estimated Fair Value	[8]	19,604,423
Mortgage Revenue Bonds Held In Trust [Member] | Ohio Properties [Member] | Series A [Member] | OH [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[6]	13,890,001		13,989,000
Cumulative Unrealized Gain	[6]	48,160		241,675
Estimated Fair Value	[6]	13,938,161		14,230,675
Mortgage Revenue Bonds Held In Trust [Member] | Bridle Ridge [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[6]	7,315,000		7,395,000
Cumulative Unrealized Gain	[6]	54,050		90,349
Estimated Fair Value	[6]	7,369,050		7,485,349
Mortgage Revenue Bonds Held In Trust [Member] | Columbia Gardens [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	13,105,293		13,222,480
Cumulative Unrealized Gain	[1]	2,157,828		1,396,828
Estimated Fair Value	[1]	15,263,121		14,619,308
Mortgage Revenue Bonds Held In Trust [Member] | Companion at Thornhill Apartments [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	11,208,284		11,294,928
Cumulative Unrealized Gain	[1]	1,729,367		1,148,219
Estimated Fair Value	[1]	12,937,651		12,443,147
Mortgage Revenue Bonds Held In Trust [Member] | Cross Creek [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[6]	6,144,672		6,143,919
Cumulative Unrealized Gain	[6]	2,520,743		2,540,949
Estimated Fair Value	[6]	8,665,415		8,684,868
Mortgage Revenue Bonds Held In Trust [Member] | The Palms at Premier Park [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	18,891,224		19,044,617
Cumulative Unrealized Gain	[3]	2,779,140		2,194,791
Estimated Fair Value	[3]	21,670,364		21,239,408
Mortgage Revenue Bonds Held In Trust [Member] | Village at River's Edge [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	9,889,108		9,938,059
Cumulative Unrealized Gain	[1]	2,330,806		1,421,114
Estimated Fair Value	[1]	12,219,914		11,359,173
Mortgage Revenue Bonds Held In Trust [Member] | Willow Run [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	12,923,882		13,040,029
Cumulative Unrealized Gain	[1]	2,126,087		1,375,542
Estimated Fair Value	[1]	15,049,969		14,415,571
Mortgage Revenue Bonds Held In Trust [Member] | Arbors at Hickory Ridge [Member] | TN [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	11,092,043		11,194,690
Cumulative Unrealized Gain	[3]	2,021,048		1,399,461
Estimated Fair Value	[3]	13,113,091		12,594,151
Mortgage Revenue Bonds Held In Trust [Member] | Rosewood Townhomes [Member] | Series A [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[4]	9,280,000
Cumulative Unrealized Gain	[4]	114,365
Estimated Fair Value	[4]	9,394,365
Mortgage Revenue Bonds Held In Trust [Member] | Pro Nova [Member] | TN [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[5]	10,023,617	[7]	10,027,413
Cumulative Unrealized Gain	[5]			19,710
Cumulative Unrealized Loss	[5],[7]	(347,124)
Estimated Fair Value	[5]	9,676,493	[7]	10,047,123
Mortgage Revenue Bonds Held In Trust [Member] | South Pointe Apartments [Member] | Series A [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[4]	21,600,000
Cumulative Unrealized Gain	[4]	362,290
Estimated Fair Value	[4]	21,962,290
Mortgage Revenue Bonds Held In Trust [Member] | Avistar at Copperfield [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[5]	13,977,000		10,000,000
Cumulative Unrealized Gain	[5]	2,333,591		589,196
Estimated Fair Value	[5]	16,310,591		10,589,196
Mortgage Revenue Bonds Held In Trust [Member] | Avistar at the Crest [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	9,279,129		9,357,374
Cumulative Unrealized Gain	[3]	1,772,133		1,036,288
Estimated Fair Value	[3]	11,051,262		10,393,662
Mortgage Revenue Bonds Held In Trust [Member] | Avistar at the Oaks [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	7,496,870		7,558,240
Cumulative Unrealized Gain	[3]	1,407,554		706,970
Estimated Fair Value	[3]	8,904,424		8,265,210
Mortgage Revenue Bonds Held In Trust [Member] | Avistar at the Parkway [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[2]	13,020,181		13,114,418
Cumulative Unrealized Gain	[2]	2,117,134		1,232,292
Estimated Fair Value	[2]	15,137,315		14,346,710
Mortgage Revenue Bonds Held In Trust [Member] | Avistar at Wilcrest [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[5]	5,297,000		3,775,000
Cumulative Unrealized Gain	[5]	818,097		206,263
Estimated Fair Value	[5]	6,115,097		3,981,263
Mortgage Revenue Bonds Held In Trust [Member] | Avistar at Wood Hollow [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[5]	40,220,000		31,850,000
Cumulative Unrealized Gain	[5]	6,546,613		1,624,687
Estimated Fair Value	[5]	46,766,613		33,474,687
Mortgage Revenue Bonds Held In Trust [Member] | Avistar in 09 [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	6,473,257		6,526,247
Cumulative Unrealized Gain	[3]	1,068,331		525,939
Estimated Fair Value	[3]	7,541,588		7,052,186
Mortgage Revenue Bonds Held In Trust [Member] | Avistar on the Boulevard [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	15,807,997		15,941,296
Cumulative Unrealized Gain	[3]	2,738,122		1,628,269
Estimated Fair Value	[3]	18,546,119		17,569,565
Mortgage Revenue Bonds Held In Trust [Member] | Avistar on the Hills [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[3]	5,179,570		5,221,971
Cumulative Unrealized Gain	[3]	996,345		557,084
Estimated Fair Value	[3]	6,175,915		5,779,055
Mortgage Revenue Bonds Held In Trust [Member] | Bruton Apartments [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	17,839,917		17,933,482
Cumulative Unrealized Gain	[1]	3,637,297		2,046,056
Estimated Fair Value	[1]	21,477,214		19,979,538
Mortgage Revenue Bonds Held In Trust [Member] | Concord at Gulfgate [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	19,018,891		19,144,400
Cumulative Unrealized Gain	[1]	3,758,251		2,222,555
Estimated Fair Value	[1]	22,777,142		21,366,955
Mortgage Revenue Bonds Held In Trust [Member] | Concord at Little York [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	13,323,633		13,411,558
Cumulative Unrealized Gain	[1]	2,757,400		1,617,217
Estimated Fair Value	[1]	16,081,033		15,028,775
Mortgage Revenue Bonds Held In Trust [Member] | Concord at Williamcrest [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	20,639,734		20,775,940
Cumulative Unrealized Gain	[1]	4,174,795		2,505,243
Estimated Fair Value	[1]	24,814,529		23,281,183
Mortgage Revenue Bonds Held In Trust [Member] | Crossing at 1415 [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	7,423,125		7,474,716
Cumulative Unrealized Gain	[1]	1,149,904		600,738
Estimated Fair Value	[1]	8,573,029		8,075,454
Mortgage Revenue Bonds Held In Trust [Member] | Decatur-Angle [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	22,500,338		22,630,276
Cumulative Unrealized Gain	[1]	3,869,765		1,945,516
Estimated Fair Value	[1]	26,370,103		24,575,792
Mortgage Revenue Bonds Held In Trust [Member] | Esperanza at Palo Alto [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	19,390,360		19,487,713
Cumulative Unrealized Gain	[1]	4,290,792		2,350,453
Estimated Fair Value	[1]	23,681,152		21,838,166
Mortgage Revenue Bonds Held In Trust [Member] | Heights at 515 [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	6,795,999		6,843,232
Cumulative Unrealized Gain	[1]	1,229,217		722,522
Estimated Fair Value	[1]	8,025,216		7,565,754
Mortgage Revenue Bonds Held In Trust [Member] | Heritage Square [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[2]	10,722,964		10,958,661
Cumulative Unrealized Gain	[2]	1,471,450		893,881
Estimated Fair Value	[2]	12,194,414		11,852,542
Mortgage Revenue Bonds Held In Trust [Member] | Oaks at Georgetown [Member] | Series A [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	12,264,411		12,330,000
Cumulative Unrealized Gain	[1]	1,750,507		693,579
Estimated Fair Value	[1]	14,014,918		13,023,579
Mortgage Revenue Bonds Held In Trust [Member] | Runnymede [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[6]	9,985,000		10,040,000
Cumulative Unrealized Gain	[6]	154,466		64,280
Estimated Fair Value	[6]	10,139,466		10,104,280
Mortgage Revenue Bonds Held In Trust [Member] | Southpark [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[6]	11,679,665		11,623,649
Cumulative Unrealized Gain	[6]	2,411,352		2,482,923
Estimated Fair Value	[6]	14,091,017		14,106,572
Mortgage Revenue Bonds Held In Trust [Member] | 15 West Apartments [Member] | WA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[1]	9,689,570		9,737,418
Cumulative Unrealized Gain	[1]	2,382,417		1,480,489
Estimated Fair Value	[1]	12,071,987		11,217,907
Mortgage Revenue Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		27,275,780		87,142,842
Cumulative Unrealized Gain		2,849,553		1,809,746
Cumulative Unrealized Loss				(2,058,026)
Estimated Fair Value		30,125,333		86,894,562
Mortgage Revenue Bonds [Member] | Courtyard [Member] | Series B [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns				6,228,000
Cumulative Unrealized Gain				2,450
Estimated Fair Value				6,230,450
Mortgage Revenue Bonds [Member] | Seasons San Juan Capistrano [Member] | Series B [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[9]			5,574,000
Cumulative Unrealized Loss	[9]			(1,078)
Estimated Fair Value	[9]			5,572,922
Mortgage Revenue Bonds [Member] | Greens Property [Member] | Series B [Member] | NC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		931,038		933,928
Cumulative Unrealized Gain		145,428		149,789
Estimated Fair Value		1,076,466		1,083,717
Mortgage Revenue Bonds [Member] | Village At Avalon [Member] | Series A [Member] | NM [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns				16,400,000
Cumulative Unrealized Gain				1,408,802
Estimated Fair Value				17,808,802
Mortgage Revenue Bonds [Member] | Ohio Properties [Member] | Series B [Member] | OH [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		3,508,510		3,520,900
Cumulative Unrealized Gain		10,480		51,334
Estimated Fair Value		3,518,990		3,572,234
Mortgage Revenue Bonds [Member] | Rosewood Townhomes [Member] | Series A and B [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[9]			9,750,000
Cumulative Unrealized Loss	[9]			(644,962)
Estimated Fair Value	[9]			9,105,038
Mortgage Revenue Bonds [Member] | Rosewood Townhomes [Member] | Series B [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		470,000
Cumulative Unrealized Gain		1,563
Estimated Fair Value		471,563
Mortgage Revenue Bonds [Member] | South Pointe Apartments [Member] | Series A and B [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns	[9]			22,700,000
Cumulative Unrealized Loss	[9]			(1,411,986)
Estimated Fair Value	[9]			21,288,014
Mortgage Revenue Bonds [Member] | South Pointe Apartments [Member] | Series B [Member] | SC [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		1,100,000
Cumulative Unrealized Gain		3,139
Estimated Fair Value		1,103,139
Mortgage Revenue Bonds [Member] | Avistar at Copperfield [Member] | Series B [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns				4,000,000
Cumulative Unrealized Gain				11,730
Estimated Fair Value				4,011,730
Mortgage Revenue Bonds [Member] | Avistar at the Crest [Member] | Series B [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		742,034		745,358
Cumulative Unrealized Gain		97,848		50,965
Estimated Fair Value		839,882		796,323
Mortgage Revenue Bonds [Member] | Avistar at the Oaks [Member] | Series B [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		542,984		545,321
Cumulative Unrealized Gain		69,234		28,738
Estimated Fair Value		612,218		574,059
Mortgage Revenue Bonds [Member] | Avistar at the Parkway [Member] | Series B [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		124,382		124,600
Cumulative Unrealized Gain		38,672		32,220
Estimated Fair Value		163,054		156,820
Mortgage Revenue Bonds [Member] | Avistar at Wilcrest [Member] | Series B [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns				1,550,000
Cumulative Unrealized Gain				4,013
Estimated Fair Value				1,554,013
Mortgage Revenue Bonds [Member] | Avistar at Wood Hollow [Member] | Series B [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns				8,410,000
Cumulative Unrealized Gain				23,940
Estimated Fair Value				8,433,940
Mortgage Revenue Bonds [Member] | Avistar in 09 [Member] | Series B [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		447,913		449,841
Cumulative Unrealized Gain		55,370		18,742
Estimated Fair Value		503,283		468,583
Mortgage Revenue Bonds [Member] | Avistar on the Boulevard [Member] | Series B [Member] | TX [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		440,919		442,894
Cumulative Unrealized Gain		54,786		27,023
Estimated Fair Value		495,705		469,917
Mortgage Revenue Bonds [Member] | Montevista [Member] | Series A and B [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		13,200,000
Cumulative Unrealized Gain		1,722,484
Estimated Fair Value		14,922,484
Mortgage Revenue Bonds [Member] | Solano Vista [Member] | Series A and B [Member] | CA [Member]
Schedule Of Available For Sale Securities [Line Items]
Cost Adjusted for Paydowns		5,768,000		5,768,000
Cumulative Unrealized Gain		650,549
Estimated Fair Value		$ 6,418,549		$ 5,768,000

[1] MRBs owned by ATAX TEBS IV, LLC (M45 TEBS), Note 15

[2] MRBs owned by ATAX TEBS III, LLC (M33 TEBS), Note 15

[3] MRBs owned by ATAX TEBS II, LLC (M31 TEBS), Note 15

[4] MRBs held by Mizuho Capital Markets, LLC in a secured financing transaction, Note 15

[5] MRBs held by Deutsche Bank in a secured financing transaction, Note 15

[6] MRBs owned by ATAX TEBS I, LLC (M24 TEBS), Note 15

[7] As of the date presented, the MRB had been in a cumulative unrealized loss for less than 12 consecutive months.

[8] MRB held by Morgan Stanley in a secured financing transaction, Note 15

[9] As of the date presented, the MRB had been in a cumulative unrealized loss position for less than 12 consecutive months.