Consolidated Statements of Changes in Equity (Unaudited) - USD ($)	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total Greystone Stockholders' Equity [Member]	Non-controlling Interest [Member]	Total
Balance at May. 31, 2018	$ 5	$ 2,836	$ 53,790,764	$ (52,485,313)	$ 1,308,292	$ 1,085,155	$ 2,393,447
Balance, shares at May. 31, 2018	50,000	28,361,201
Cash distributions						(51,000)	(51,000)
Preferred dividends				(102,945)	(102,945)		(102,945)
Net income				704,333	704,333	60,575	764,908
Balance at Aug. 31, 2018	$ 5	$ 2,836	53,790,764	(51,883,925)	1,909,680	1,094,730	3,004,410
Balance, shares at Aug. 31, 2018	50,000	28,361,201
Balance at May. 31, 2019	$ 5	$ 2,836	53,790,764	(51,108,677)	2,684,928	1,126,271	3,811,199
Balance, shares at May. 31, 2019	50,000	28,361,201
Cash distributions						(52,200)	(52,200)
Preferred dividends				(112,363)	(112,363)		(112,363)
Net income				554,613	554,613	64,686	619,299
Balance at Aug. 31, 2019	$ 5	$ 2,836	$ 53,790,764	$ (50,666,427)	$ 3,127,178	$ 1,138,757	$ 4,265,935
Balance, shares at Aug. 31, 2019	50,000	28,361,201