RELATED PARTY TRANSACTIONS - Fund management fees paid (Details) - USD ($)	6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Related Party Transaction [Line Items]
Fund management fees paid	$ 562,339	$ 2,883,556
Series Twenty Four [Member]
Related Party Transaction [Line Items]
Fund management fees paid	0	20,598
Series Twenty Six [Member]
Related Party Transaction [Line Items]
Fund management fees paid	4,282	27,876
Series Twenty Seven [Member]
Related Party Transaction [Line Items]
Fund management fees paid	0	15,270
Series Twenty Eight [Member]
Related Party Transaction [Line Items]
Fund management fees paid	0	14,592
Series Thirty One [Member]
Related Party Transaction [Line Items]
Fund management fees paid	0	4,308
Series Thirty Two [Member]
Related Party Transaction [Line Items]
Fund management fees paid	0	51,208
Series Thirty Three [Member]
Related Party Transaction [Line Items]
Fund management fees paid	9,777	1,125,921
Series Thirty Five [Member]
Related Party Transaction [Line Items]
Fund management fees paid	0	20,500
Series Thirty Six [Member]
Related Party Transaction [Line Items]
Fund management fees paid	0	7,911
Series Thirty Eight [Member]
Related Party Transaction [Line Items]
Fund management fees paid	0	19,323
Series Forty [Member]
Related Party Transaction [Line Items]
Fund management fees paid	0	1,188,699
Series Forty Two [Member]
Related Party Transaction [Line Items]
Fund management fees paid	19,259	47,580
Series Forty Three [Member]
Related Party Transaction [Line Items]
Fund management fees paid	21,348	223,770
Series Forty Five [Member]
Related Party Transaction [Line Items]
Fund management fees paid	$ 507,673	$ 116,000