Pension And Other Postretirement Benefit Plans (Components Of Company's Net Periodic Benefit Cost) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,483	$ 1,334
Interest cost	2,346	2,669
Expected return on plan assets	(3,576)	(3,692)
Net amortization and deferral	1,199	780
Net periodic benefit cost	1,452	1,091
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	108	114
Interest cost	407	484
Expected return on plan assets	(15)	(26)
Net amortization and deferral	(44)	(133)
Net periodic benefit cost	$ 456	$ 439