Impact of Adoption of New Accounting Standards - Comprehensive (loss) income (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2015
Impact of Adoption of New Accounting Standards
Net income	$ 47,419	$ 17,647	$ 13,078	$ 13,078
Other comprehensive income:
Change in foreign currency translation adjustments	(34)	36
Unrealized gain on investments	57	70	74	74
Total comprehensive income	47,442	17,753	13,152	13,152
Net loss attributable to noncontrolling interest	19	216	22	22
Comprehensive income (loss) attributable to AeroVironment	$ 47,461	17,969	13,174	$ 13,174
ASU 2014-09 | As Reported.
Impact of Adoption of New Accounting Standards
Net income		19,852	12,457
Other comprehensive income:
Change in foreign currency translation adjustments		36
Unrealized gain on investments		70	74
Total comprehensive income		19,958	12,531
Net loss attributable to noncontrolling interest		216	22
Comprehensive income (loss) attributable to AeroVironment		20,174	12,553
ASU 2014-09 | Adjustment
Impact of Adoption of New Accounting Standards
Net income		(2,205)	621
Other comprehensive income:
Total comprehensive income		(2,205)	621
Comprehensive income (loss) attributable to AeroVironment		$ (2,205)	$ 621