INVESTMENTS IN OPERATING PARTNERSHIPS - Contributions Payable (Details) - USD ($)	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018
Contributions Payable [Line Items]
Capital contributions payable	$ 18,554	$ 18,554	$ 26,447
Series 15
Contributions Payable [Line Items]
Capital contributions payable	0	0	0
Series 16
Contributions Payable [Line Items]
Capital contributions payable	0	0	0
Series 17
Contributions Payable [Line Items]
Capital contributions payable	0	0	7,893
Series 18
Contributions Payable [Line Items]
Capital contributions payable	18,554	18,554	18,554
Series 19
Contributions Payable [Line Items]
Capital contributions payable	$ 0	$ 0	$ 0