Accounts Receivable (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	Jan. 31, 2018
Concentration Risk [Line Items]
Receivables, Long-term Contracts or Programs			$ 3.2
Accounts Receivable, Additional Narrative Disclosure	outstanding for several years as of April 30, 2018. The Company completed all of its deliverables in 2015, and has been engaged in ongoing active efforts to collect this amount, and has recently received an updated acknowledgment of the outstanding balances and assurances of payment from the customer. As a result, the Company did not reserve any allowance against this amount as of April 30, 2018. However, if the Company’s efforts to collect on this account are not successful in fiscal 2018, then the Company may be required to recognize an allowance for all, or substantially all, of any such then uncollected amounts in the future.
Accounts Receivable [Member]
Concentration Risk [Line Items]
Accounts Receivable, Gross			5.4
Receivables, Long-term Contracts or Programs			$ 3.7
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	16.30%		34.90%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	13.50%	11.00%