Employee Benefit Plans (Components of net periodic benefit costs post retirement benefits) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Postemployment Benefits [Abstract]
Service cost for benefits earned during the period	$ 317	$ 292	$ 950	$ 876
Other components of net periodic benefit costs:
Interest cost on accumulated postretirement benefit	230	241	689	723
Other components	17	22	51	67
Total other components of net periodic benefit costs	247	263	740	790
Net periodic postretirement benefit cost	$ 564	$ 555	$ 1,690	$ 1,666