Pension And Other Postretirement Benefit Plans (Additional Information On Funded Status) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Pension Benefits [Member]
For Plans With A Projected Benefit Obligation In Excess Of Plan Assets:
Aggregate projected benefit obligation (PBO)	$ 269,622	$ 261,581
Aggregate fair value of plan assets	234,565	215,182
For Plans With An Accumulated Benefit Obligation In Excess Of Plan Assets:
Aggregate accumulated benefit obligation (ABO)	35,070	258,708
Aggregate fair value of plan assets	4,023	215,182
Other Postretirement Benefits [Member]
For Plans With A Projected Benefit Obligation In Excess Of Plan Assets:
Aggregate projected benefit obligation (PBO)	31,635	32,945
Aggregate fair value of plan assets	$ 3,717	$ 3,467