Employee Benefit Plans (Components of Postretirement Benefit Liabilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning of year	$ 30,755	$ 27,503
Service cost for benefits earned during the period	1,401	1,267	$ 1,055
Interest cost on accumulated post retirement benefit	908	919	964
Net benefit payments and expense	(1,021)	(841)
Actuarial loss	(1,837)	1,907
Accumulated postretirement benefit obligation	30,206	30,755	$ 27,503
Liabilities:
Current liabilities	1,449	1,334
Non-currrent liabilities	28,757	29,421
Total post retirement benefit liability recognized in statement of financial position	30,206	30,755
Components included in accumulated other comprehensive income (loss):
Unrecognized net loss	(3,237)	(5,286)
Cumulative net periodic benefit cost (in excess of employer contribution)	$ 26,969	$ 25,469