Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (49,257)	$ 18,445	$ (44,246)	$ 57,626
Other comprehensive income, net of tax:
Change in pension benefits, net of deferred taxes of $18,230 and $111, and $18,481 and $338 for the three and nine months ended January 31, 2022 and 2021, respectively	53,822	328	54,568	984
Change in cash flow hedges (swap), net of deferred taxes of $763 and $1,404 for the three and nine months ended January 31, 2022, respectively	2,253	0	4,145	0
Total Comprehensive Income	$ 6,818	$ 18,773	$ 14,467	$ 58,610