Pension And Other Postretirement Benefit Plans (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2031
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss expected in net periodic benefit cost during next fiscal year	$ 400
Prior service benefit expected in net periodic benefit cost during next fiscal year	$ 200
Percentage of total plan assets	97.00%
Percentage of total projected benefit obligation	85.00%
Pension and Other Postretirement Benefits Cost (Reversal of Cost)	$ 3,400	$ 3,000	$ 2,900
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of the plans, end of year	$ 19,446	$ 21,037
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Revised healthcare cost trend assumption	6.97%	6.17%	6.17%
Year that rate reaches healthcare cost trend rate	2032
Funded status of the plans, end of year	$ 18,459	$ 22,251
Other Postretirement Benefits [Member] | Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Revised healthcare cost trend assumption				4.44%
ERISA Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected company contributions in next fiscal year	0
Nonqualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected company contributions in next fiscal year	4,500
Nonqualified Plan [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of the plans, end of year	29,400
Nonqualified Plan [Member] | Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of the plans, end of year	$ 17,000