Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2019	Jul. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 26,881	$ 24,767
Other comprehensive income, net of tax:
Change in pension benefits, net of deferred taxes of $107 and $105 for the three months ended July 31, 2019 and 2018, respectively	315	307
Total Comprehensive Income	$ 27,196	$ 25,074