Pension And Other Postretirement Benefit Plans (Recognized In Accumulated Other Comprehensive Income (Loss) On Pretax Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain), beginning of year	$ 64,114	$ 67,280
Losses (gains) arising during the year	107	(98)
Amortization included in net periodic benefit cost during the year	(793)	(3,068)
Net actuarial loss (gain), end of year	63,428	64,114	$ 67,280
Prior service cost (benefit), beginning of year	(457)	(1,487)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax	692	0
Amortization included in net periodic benefit cost during the year	134	1,030
Prior service cost (benefit), end of year	369	(457)	(1,487)
Total amounts in accumulated other comprehensive loss at end of year, before income taxes	63,797	63,657
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain), beginning of year	(8,332)	(6,681)
Losses (gains) arising during the year	377	(2,223)
Amortization included in net periodic benefit cost during the year	(786)	(572)
Net actuarial loss (gain), end of year	(7,169)	(8,332)	(6,681)
Prior service cost (benefit), beginning of year	(36)	(201)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax	0		0
Amortization included in net periodic benefit cost during the year	5	165
Prior service cost (benefit), end of year	(31)	(36)	$ (201)
Total amounts in accumulated other comprehensive loss at end of year, before income taxes	$ (7,200)	$ (8,368)