INVESTMENTS IN OPERATING PARTNERSHIPS (Details 3) - USD ($)		3 Months Ended
		Mar. 31, 2015	Mar. 31, 2014
Revenues
Rental		$ 3,263,242	$ 5,018,236
Interest and other		62,042	122,887
Operating Partnerships Revenues		3,325,284	5,141,123
Expenses
Interest		408,660	695,315
Depreciation and amortization		845,960	1,285,448
Operating expenses		2,514,133	3,835,600
Operating Partnerships Total Expenses		3,768,753	5,816,363
NET LOSS		(443,469)	(675,240)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[1]	(439,032)	(668,486)
Net Income (Loss) allocated to other partners		(4,437)	(6,754)
Series Fifteen [Member]
Revenues
Rental		725,157	935,673
Interest and other		12,202	17,653
Operating Partnerships Revenues		737,359	953,326
Expenses
Interest		98,002	128,421
Depreciation and amortization		187,833	231,481
Operating expenses		560,078	692,690
Operating Partnerships Total Expenses		845,913	1,052,592
NET LOSS		(108,554)	(99,266)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[2]	(107,468)	(98,273)
Net Income (Loss) allocated to other partners		(1,086)	(993)
Series Sixteen [Member]
Revenues
Rental		1,126,696	1,377,097
Interest and other		16,743	19,129
Operating Partnerships Revenues		1,143,439	1,396,226
Expenses
Interest		144,524	197,712
Depreciation and amortization		290,726	349,083
Operating expenses		814,159	1,096,998
Operating Partnerships Total Expenses		1,249,409	1,643,793
NET LOSS		(105,970)	(247,567)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[3]	(104,910)	(245,091)
Net Income (Loss) allocated to other partners		(1,060)	(2,476)
Series Seventeen [Member]
Revenues
Rental		700,583	1,437,760
Interest and other		12,712	28,887
Operating Partnerships Revenues		713,295	1,466,647
Expenses
Interest		88,135	181,486
Depreciation and amortization		195,800	338,004
Operating expenses		533,854	1,057,152
Operating Partnerships Total Expenses		817,789	1,576,642
NET LOSS		(104,494)	(109,995)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[4]	(103,448)	(108,894)
Net Income (Loss) allocated to other partners		(1,046)	(1,101)
Series Eighteen [Member]
Revenues
Rental		523,605	933,455
Interest and other		16,560	34,624
Operating Partnerships Revenues		540,165	968,079
Expenses
Interest		54,430	118,785
Depreciation and amortization		131,150	286,504
Operating expenses		442,777	710,705
Operating Partnerships Total Expenses		628,357	1,115,994
NET LOSS		(88,192)	(147,915)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[5]	(87,310)	(146,436)
Net Income (Loss) allocated to other partners		(882)	(1,479)
Series Nineteen [Member]
Revenues
Rental		187,201	334,251
Interest and other		3,825	22,594
Operating Partnerships Revenues		191,026	356,845
Expenses
Interest		23,569	68,911
Depreciation and amortization		40,451	80,376
Operating expenses		163,265	278,055
Operating Partnerships Total Expenses		227,285	427,342
NET LOSS		(36,259)	(70,497)
Net loss allocated to Boston Capital Tax Credit Fund III L.P.	[6]	(35,896)	(69,792)
Net Income (Loss) allocated to other partners		$ (363)	$ (705)

[1] Amounts include $439,032 and $668,486 for 2015 and 2014, respectively, of loss not recognized under the equity method of accounting.

[2] Amounts include $107,468 and $98,273 for 2015 and 2014, respectively, of loss not recognized under the equity method of accounting.

[3] Amounts include $104,910 and $245,091 for 2015 and 2014, respectively, of loss not recognized under the equity method of accounting.

[4] Amounts include $103,448 and $108,894 for 2015 and 2014, respectively, of loss not recognized under the equity method of accounting.

[5] Amounts include $87,310 and $146,436 for 2015 and 2014, respectively, of loss not recognized under the equity method of accounting.

[6] Amounts include $35,896 and $69,792 for 2015 and 2014, respectively, of loss not recognized under the equity method of accounting.