Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 58,763	$ 74,861	$ 83,688
Other comprehensive (loss) net of tax:
Change in pension benefits, net of deferred taxes of $(1,156), $(573), and $190, respectively	(3,395)	(1,682)	(422)
Total Comprehensive Income	$ 55,368	$ 73,179	$ 83,266