Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	6 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Apr. 30, 2019
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 9,355		$ 7,287
Unrecognized tax benefits that would impact effective tax rate	7,412
Accrued interest and penalties related to unrecognized tax benefits	361		$ 242
Net interest and penalties included in income tax expense	119	$ 77
Expected decrease in unrecognized tax benefits	$ 1,100