Significant Customers - Narrative (Details) - USD ($)	12 Months Ended
	Apr. 30, 2018	Apr. 30, 2017
Customer One
Revenue, Major Customer [Line Items]
Revenues	$ 4,200,000	$ 3,300,000
Accounts receivable, gross	$ 878,530	$ 994,095
Customer One | Revenue
Revenue, Major Customer [Line Items]
Concentration risk percentage	20.60%	21.30%
Customer One | Accounts Receivable
Revenue, Major Customer [Line Items]
Concentration risk percentage	22.60%	43.70%
Customer Two
Revenue, Major Customer [Line Items]
Revenues	$ 2,600,000
Accounts receivable, gross	$ 736,071	$ 256,022
Customer Two | Revenue
Revenue, Major Customer [Line Items]
Concentration risk percentage	12.80%
Customer Two | Accounts Receivable
Revenue, Major Customer [Line Items]
Concentration risk percentage	19.00%	11.30%