Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Apr. 30, 2019
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 8,381		$ 7,287
Unrecognized tax benefits that would impact effective tax rate	6,643
Accrued interest and penalties related to unrecognized tax benefits	299		$ 242
Net interest and penalties included in income tax expense	57	$ 32
Expected decrease in unrecognized tax benefits	$ 1,100