Pension And Other Postretirement Benefit Plans (Recognized In Accumulated Other Comprehensive Income (Loss) On Pretax Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain), beginning of year	$ 81,544	$ 70,488
Losses (gains) arising during the year	4,787	23,353
Reclassification adjustments during the year	7,032	12,297
Net actuarial loss (gain), end of year	79,299	81,544
Prior service cost (benefit), beginning of year	(17,630)	(22,998)
Prior service cost (benefit) arising during the year	111	(675)
Reclassification adjustments during the year	2,458	6,043
Prior service cost (benefit), end of year	(15,061)	(17,630)
Total amounts in accumulated other comprehensive loss at end of year, before income taxes	64,238	63,914
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain), beginning of year	(6,402)	(9,952)
Losses (gains) arising during the year	(1,263)	2,879
Reclassification adjustments during the year	(431)	(671)
Net actuarial loss (gain), end of year	(7,234)	(6,402)
Prior service cost (benefit), beginning of year	0	0
Prior service cost (benefit) arising during the year	(108)	0
Reclassification adjustments during the year	0	0
Prior service cost (benefit), end of year	(108)	0
Total amounts in accumulated other comprehensive loss at end of year, before income taxes	$ (7,342)	$ (6,402)