Pension And Other Postretirement Benefit Plans (Components Of Company's Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,545	$ 1,650
Interest cost	2,335	2,259
Expected return on plan assets	(3,324)	(3,385)
Net amortization and deferral	1,001	976
Net periodic benefit cost	1,557	1,500
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	32	47
Interest cost	241	239
Expected return on plan assets	(19)	(22)
Net amortization and deferral	(172)	(115)
Net periodic benefit cost	$ 82	$ 149