Pension And Other Postretirement Benefit Plans (Fair Values Of Assets Under Fair Value Hierarchy) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Mar. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Total investments	$ 199,525	$ 195,715
Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	81,445	80,068
International Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	20,935	23,925
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	79,261	74,761
Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	8,358	8,338
Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	9,526	8,623
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	68,430	68,199
Level 1 [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	26,025	27,300
Level 1 [Member] | International Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	20,935	23,925
Level 1 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	21,470	16,974
Level 1 [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	0	0
Level 1 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	0	0
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	107,128	105,193
Level 2 [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	55,420	52,768
Level 2 [Member] | International Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	0	0
Level 2 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	51,708	52,425
Level 2 [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	0	0
Level 2 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	0	0
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	23,967	22,323
Level 3 [Member] | Domestic Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	0	0
Level 3 [Member] | International Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	0	0
Level 3 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	6,083	5,362
Level 3 [Member] | Real Estate Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	8,358	8,338
Level 3 [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	$ 9,526	$ 8,623