Employee Benefit Plans (Components of net periodic benefit costs post retirement benefits) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Postemployment Benefits [Abstract]
Service cost for benefits earned during the period	$ 351	$ 316	$ 701	$ 633
Other components of net periodic benefit costs:
Interest cost on accumulated postretirement benefit	227	229	454	459
Other components	53	17	106	34
Total other components of net periodic benefit costs	280	246	560	493
Net periodic postretirement benefit cost	$ 631	$ 562	$ 1,261	$ 1,126