Employee Benefit Plans (Components of net periodic benefit costs post retirement benefits) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Postemployment Benefits [Abstract]
Service cost for benefits earned during the period	$ 240	$ 206	$ 480	$ 413
Interest cost on accumulated postretirement benefit	188	180	376	360
Other components	9	4	18	7
Net periodic postretirement benefit cost	$ 437	$ 390	$ 874	$ 780