Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Feb. 28, 2019	May 31, 2018
Stockholders' equity [note 3]
Common stock par value	$ 0.001	$ 0.001
Common stock authorized	80,000,000	80,000,000
Common stock issued	41,006,497	29,520,560
Common stock outstanding	41,006,497	29,520,560
Preferred Stock Series 2012 [Member]
Stockholders' equity [note 3]
Preferred stock par value	$ 0.001	$ 0.001
Preferred stock authorized	20,000,000	20,000,000
Preferred stock issued	445,000	445,000
Preferred stock outstanding	445,000	445,000
Preferred Stock Series A-2014 [Member]
Stockholders' equity [note 3]
Preferred stock par value	$ 0.001	$ 0.001
Preferred stock authorized	20,000,000	20,000,000
Preferred stock issued	356,000	606,000
Preferred stock outstanding	356,000	606,000
Preferred Stock Series C-2016 [Member]
Stockholders' equity [note 3]
Preferred stock par value	$ 0.001	$ 0.001
Preferred stock authorized	20,000,000	20,000,000
Preferred stock issued	363,000	622,958
Preferred stock outstanding	363,000	622,958
Preferred Stock Series D-2017 [Member]
Stockholders' equity [note 3]
Preferred stock par value	$ 0.001	$ 0.001
Preferred stock authorized	20,000,000	20,000,000
Preferred stock issued	6,572,050	6,643,050
Preferred stock outstanding	6,572,050	6,643,050