Consolidated Statements of Changes in Deficit - USD ($)	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total Greystone Stockholders' Deficit [Member]	Variable Interest Entity [Member]	Total
Balance at May. 31, 2013	$ 5	$ 2,611	$ 53,142,717	$ (58,321,266)	$ (5,175,933)	$ 1,139,878	$ (4,036,055)
Balance, Shares at May. 31, 2013	50,000	26,111,201
Common stock options exercised		$ 35	139,965		140,000		$ 140,000
Common stock options exercised, Shares		350,000					(350,000)
Stock based compensation			53,424		53,424		$ 53,424
Cash distributions						(347,318)	(347,318)
Preferred dividends				(325,000)	(325,000)		(325,000)
Net income				2,931,063	2,931,063	200,563	3,131,626
Balance at May. 31, 2014	$ 5	$ 2,646	53,336,106	(55,715,203)	(2,376,446)	993,123	(1,383,323)
Balance, Shares at May. 31, 2014	50,000	26,461,201
Common stock options exercised		$ 95	113,905		114,000		$ 114,000
Common stock options exercised, Shares		950,000					(950,000)
Stock based compensation			53,424		53,424		$ 53,424
Cash distributions						(204,000)	(204,000)
Preferred dividends				(325,000)	(325,000)		(325,000)
Net income				382,565	382,565	227,004	609,569
Balance at May. 31, 2015	$ 5	$ 2,741	$ 53,503,435	$ (55,657,638)	$ (2,151,457)	$ 1,016,127	$ (1,135,330)
Balance, Shares at May. 31, 2015	50,000	27,411,201