Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 16,485	$ 26,881
Other comprehensive income, net of tax:
Change in pension benefits, net of deferred taxes of $113 and $107 for the three months ended July 31, 2020 and 2019, respectively	327	315
Total Comprehensive Income	$ 16,812	$ 27,196