Net Periodic Benefit Cost (Components of net periodic pension cost and net periodic postretirement benefit cost) (Details) - Pension Plans, Defined Benefiit - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Service costs	$ 128	$ 180
Interest cost	3,472	2,870
Expected return on plan assets	(2,946)	(2,713)
Net amortization	101	208
Net periodic pension (benefit) cost	$ 796	$ 545