RELATED PARTY TRANSACTIONS - Fund management fees paid (Details) - USD ($)	6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Related Party Transaction [Line Items]
Fund management fees paid	$ 2,883,556	$ 4,842,166
Series Twenty [Member]
Related Party Transaction [Line Items]
Fund management fees paid		193,337
Series Twenty Two [Member]
Related Party Transaction [Line Items]
Fund management fees paid		25,000
Series Twenty Three [Member]
Related Party Transaction [Line Items]
Fund management fees paid		250,000
Series Twenty Four [Member]
Related Party Transaction [Line Items]
Fund management fees paid	20,598	21,522
Series Twenty Six [Member]
Related Party Transaction [Line Items]
Fund management fees paid	27,876	29,547
Series Twenty Seven [Member]
Related Party Transaction [Line Items]
Fund management fees paid	15,270	15,270
Series Twenty Eight [Member]
Related Party Transaction [Line Items]
Fund management fees paid	14,592	16,140
Series Twenty Nine [Member]
Related Party Transaction [Line Items]
Fund management fees paid		519,601
Series Thirty [Member]
Related Party Transaction [Line Items]
Fund management fees paid		185,027
Series Thirty One [Member]
Related Party Transaction [Line Items]
Fund management fees paid	4,308	35,627
Series Thirty Two [Member]
Related Party Transaction [Line Items]
Fund management fees paid	51,208	787,880
Series Thirty Three [Member]
Related Party Transaction [Line Items]
Fund management fees paid	1,125,921	206,940
Series Thirty Four [Member]
Related Party Transaction [Line Items]
Fund management fees paid		150,000
Series Thirty Five [Member]
Related Party Transaction [Line Items]
Fund management fees paid	20,500	21,306
Series Thirty Six [Member]
Related Party Transaction [Line Items]
Fund management fees paid	7,911	13,616
Series Thirty Seven [Member]
Related Party Transaction [Line Items]
Fund management fees paid		526,729
Series Thirty Eight [Member]
Related Party Transaction [Line Items]
Fund management fees paid	19,323	53,049
Series Forty [Member]
Related Party Transaction [Line Items]
Fund management fees paid	1,188,699	225,000
Series Forty One [Member]
Related Party Transaction [Line Items]
Fund management fees paid		520,930
Series Forty Two [Member]
Related Party Transaction [Line Items]
Fund management fees paid	47,580	56,839
Series Forty Three [Member]
Related Party Transaction [Line Items]
Fund management fees paid	223,770	566,306
Series Forty Five [Member]
Related Party Transaction [Line Items]
Fund management fees paid	$ 116,000	242,500
Series Forty Six [Member]
Related Party Transaction [Line Items]
Fund management fees paid		$ 180,000