Impact of Adoption of New Accounting Standards - Balance Sheet (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 30, 2019	Apr. 30, 2018
Revenue from Contract with Customer [Abstract]
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 1,041	$ 1,080
Due from Related Parties	$ 9,028	$ 3,145
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, Authorized shares	10,000,000	10,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, Authorized shares	100,000,000	100,000,000
Common stock, Issued shares	23,946,293	23,908,736
Common stock, outstanding shares	23,946,293	23,908,736