Employee Benefit Plans (Components of net periodic benefit costs post retirement benefits) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Postemployment Benefits [Abstract]
Service cost for benefits earned during the period	$ 317	$ 292
Other components of net periodic benefit costs:
Interest cost on accumulated postretirement benefit	230	241
Other components	17	22
Total other components of net periodic benefit costs	247	263
Net periodic postretirement benefit cost	$ 564	$ 555