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, 2023	Mar. 31, 2022
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain), beginning of year	$ 67,280	$ 72,605
Losses (gains) arising during the year	(98)	(1,727)
Amortization included in net periodic benefit cost during the year	3,068	3,598
Net actuarial loss (gain), end of year	64,114	67,280
Prior service cost (benefit), beginning of year	(1,487)	(3,406)
Amortization included in net periodic benefit cost during the year	1,030	1,919
Prior service cost (benefit), end of year	(457)	(1,487)
Total amounts in accumulated other comprehensive loss at end of year, before income taxes	63,657	65,793
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain), beginning of year	(6,681)	(4,395)
Losses (gains) arising during the year	(2,223)	(2,533)
Amortization included in net periodic benefit cost during the year	(572)	(247)
Net actuarial loss (gain), end of year	(8,332)	(6,681)
Prior service cost (benefit), beginning of year	(201)	(376)
Amortization included in net periodic benefit cost during the year	165	175
Prior service cost (benefit), end of year	(36)	(201)
Total amounts in accumulated other comprehensive loss at end of year, before income taxes	$ (8,368)	$ (6,882)