Federal Income Taxes - Summary of Net Change in Deferred Taxes (Details) - USD ($)	12 Months Ended
	May 31, 2017	May 31, 2016
Income Tax Disclosure [Abstract]
Net operating loss carryforward	$ (229,465)	$ 396,246
Depreciation and amortization, tax reporting in excess of financial	(911,766)	(906,087)
Stock compensation costs	18,124	3,714
Allowance for doubtful accounts	4,280
Accrued expenses	113,021
Other	3,539	10,572
Net decrease	$ (1,002,267)	$ (495,555)