Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 17,195	$ 12,804	$ 55,936	$ 61,848
Other comprehensive income, net of tax:
Change in pension benefits, net of deferred taxes of $111 and $107, and $338 and $322 for the three and nine months ended January 31, 2021 and 2020, respectively	328	315	984	946
Total Comprehensive Income	$ 17,523	$ 13,119	$ 56,920	$ 62,794