Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Oct. 31, 2017	Apr. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	$ 171,913	$ 179,759
Total definite-lived intangible assets, Accumulated Amortization	(48,720)	(38,668)
Total definite-lived intangible assets, Net Carrying Amount	123,193	141,091
Indefinite-lived intangible assets, Net Carrying Amount	226	226
Total Intangible assets, Gross Carrying Amount	172,139	179,985
Total Intangible assets, Net Carrying Amount	123,419	141,317
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	92,360	105,260
Total definite-lived intangible assets, Accumulated Amortization	(21,843)	(16,463)
Total definite-lived intangible assets, Net Carrying Amount	70,517	88,797
Developed technology
Finite-Lived Intangible Assets [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	21,130	19,430
Total definite-lived intangible assets, Accumulated Amortization	(6,696)	(5,436)
Total definite-lived intangible assets, Net Carrying Amount	14,434	13,994
Patents, trademarks, and trade names
Finite-Lived Intangible Assets [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	56,640	53,308
Total definite-lived intangible assets, Accumulated Amortization	(19,031)	(15,619)
Total definite-lived intangible assets, Net Carrying Amount	37,609	37,689
Backlog
Finite-Lived Intangible Assets [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	1,150	1,150
Total definite-lived intangible assets, Accumulated Amortization	(1,150)	(1,150)
Definite-lived intangible assets excluding patents in progress
Finite-Lived Intangible Assets [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	171,280	179,148
Total definite-lived intangible assets, Accumulated Amortization	(48,720)	(38,668)
Total definite-lived intangible assets, Net Carrying Amount	122,560	140,480
Patents in progress
Finite-Lived Intangible Assets [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	633	611
Total definite-lived intangible assets, Net Carrying Amount	$ 633	$ 611