Pension And Other Postretirement Benefit Plans (Components Of Company's Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,503	$ 1,653	$ 3,048	$ 3,303
Interest cost	2,351	2,254	4,686	4,513
Expected return on plan assets	(3,324)	(3,387)	(6,648)	(6,772)
Net amortization and deferral	1,001	976	2,002	1,952
Net periodic benefit cost	1,531	1,496	3,088	2,996
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	32	47	64	94
Interest cost	235	241	476	480
Expected return on plan assets	(19)	(22)	(38)	(44)
Net amortization and deferral	(167)	(116)	(339)	(231)
Net periodic benefit cost	$ 81	$ 150	$ 163	$ 299