Presentation and Summary of Significant Accounting Policies - Acquisition-Related Intangible Assets (Details) - Acquired Finite Lived Intangible Assets - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisition-related intangible assets	$ 8,140	$ 8,140
Accumulated amortization	(5,408)	(3,020)
Total amortization expense	$ 2,732	5,120
Current Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization in Years	3 years
Acquisition-related intangible assets	$ 6,000	6,000
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization in Years	8 years
Acquisition-related intangible assets	$ 1,700	1,700
Non-compete
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization in Years	3 years
Acquisition-related intangible assets	$ 100	100
Trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization in Years	3 years
Acquisition-related intangible assets	$ 340	$ 340