Pension And Other Postretirement Benefit Plans (Recognized In Accumulated Other Comprehensive Income (Loss) On Pretax Basis) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain), beginning of year	$ 108,171	$ 75,138
Losses (gains) arising during the year	(928)	39,461
Reclassification adjustments during the year	(13,886)	(6,428)
Net actuarial loss (gain), end of year	93,357	108,171
Prior service cost (benefit), beginning of year	(3,080)	(3,393)
Prior service cost (benefit) arising during the year	0	0
Reclassification adjustments during the year	463	313
Prior service cost (benefit), end of year	(2,617)	(3,080)
Total amounts in accumulated other comprehensive loss at end of year, before income taxes	90,740	105,091
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain), beginning of year	(4,644)	(6,722)
Losses (gains) arising during the year	717	1,475
Reclassification adjustments during the year	9	603
Net actuarial loss (gain), end of year	(3,918)	(4,644)
Prior service cost (benefit), beginning of year	500	0
Prior service cost (benefit) arising during the year	0	750
Reclassification adjustments during the year	(274)	(250)
Prior service cost (benefit), end of year	226	500
Total amounts in accumulated other comprehensive loss at end of year, before income taxes	$ (3,692)	$ (4,144)