INVESTMENTS IN OPERATING PARTNERSHIPS - Operating Partnerships within the Fund (Details) - item	Sep. 30, 2019	Sep. 30, 2018
Number Of Operating Partnerships
Number Of Operating Partnerships	112	150
Series Twenty [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships		1
Series Twenty Two [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships		3
Series Twenty Three [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships		3
Series Twenty Four [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	4	5
Series Twenty Six [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	8	8
Series Twenty Seven [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	2	3
Series Twenty Eight [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	3	4
Series Twenty Nine [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	5	5
Series Thirty [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships		2
Series Thirty One [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships		6
Series Thirty Two [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	5	5
Series Thirty Three [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	2	3
Series Thirty Four [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	3	4
Series Thirty Five [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	1	2
Series Thirty Six [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	1	2
Series Thirty Eight [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	1	3
Series Forty [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	5	8
Series Forty One [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	11	11
Series Forty Two [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	9	10
Series Forty Three [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	11	16
Series Forty Four [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	5	7
Series Forty Five [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	22	25
Series Forty Six [Member]
Number Of Operating Partnerships
Number Of Operating Partnerships	14	14