Pension And Other Postretirement Benefit Plans (Fair Values Of Assets Under Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total investments	$ 244,969	$ 229,568
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	71,561	58,667
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	164,222	156,715	[1]
Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	9,186	14,186
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	221,359	200,996
Level 1 [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	71,561	58,667
Level 1 [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	149,798	142,329	[1]
Level 1 [Member] | Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	0	0
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	10,399	10,836
Level 2 [Member] | 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	10,399	10,836	[1]
Level 2 [Member] | Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	0	0
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	13,211	17,736
Level 3 [Member] | 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	4,025	3,550	[1]
Level 3 [Member] | Alternative Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total investments	$ 9,186	$ 14,186

[1] Includes high yield securities and cash and cash equivalent balances.