Employee Benefit Plans (Components of net periodic benefit costs post retirement benefits) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Postemployment Benefits [Abstract]
Service cost for benefits earned during the period	$ 292	$ 277
Other components of net periodic benefit costs:
Interest cost on accumulated postretirement benefit	241	236
Other components	22	17
Net periodic postretirement benefit cost	$ 555	$ 530