Pension And Other Postretirement Benefit Plans (Components Of Company's Net Periodic Benefit Cost) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,327	$ 1,197	$ 2,661	$ 2,392
Interest cost	2,656	2,865	5,325	5,722
Expected return on plan assets	(3,535)	(3,543)	(7,227)	(7,085)
Curtailment gain	0	0	0	0
Net amortization and deferral	780	2,447	1,560	4,894
Net periodic benefit cost	1,228	2,966	2,319	5,923
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	114	131	228	269
Interest cost	481	508	965	1,040
Expected return on plan assets	(26)	(30)	(52)	(60)
Curtailment gain	(1,503)	0	(1,503)	0
Net amortization and deferral	(133)	(17)	(266)	(34)
Net periodic benefit cost	$ (1,067)	$ 592	$ (628)	$ 1,215