Presentation and Summary of Significant Accounting Policies - Intangible Assets Including Acquisition-Related Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 2,732	$ 5,120
Amortization expense	(1,600)	(2,388)
Ending balance	1,132	2,732
Supply Chain Management
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	2,732	5,120
Amortization expense	(1,600)	(2,388)
Ending balance	1,132	2,732
IT Consulting
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	0	0
Amortization expense	0	0
Ending balance	0	0
Other
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	0	0
Amortization expense	0	0
Ending balance	$ 0	$ 0