Retirement Plans and Other Postretirement Benefits (Narrative) (Details) $ in Thousands	12 Months Ended
	Mar. 31, 2022 USD ($) item	Mar. 31, 2021 USD ($)
Defined Contribution Plan Disclosure [Line Items]
Number of defined contribution plans employee may participate in | item	1
Defined contribution plan, expense	$ 30,780	$ 30,931
Post-Employment Benefits [Member]
Defined Contribution Plan Disclosure [Line Items]
Benefit obligation	$ 1,845	$ 1,960