Defined Benefit Pension Plans - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Retirement Benefits [Abstract]
Employer contributions	$ 0	$ 0	$ 0	$ 0
Assumed as expected long-term rate of return (as a percent)			7.75%	7.75%