Retirement Benefits (Schedule of Accumulated Benefit Obligations In Excess of and Less Than Fair Value of Plan Assets) (Details) - Defined Benefit Pension Plan [Member] - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Plans with accumulated benefit obligation in excess of plan assets
Projected benefit obligation, plans with ABO in excess of plan assets	$ (82,447)	$ (220,788)
Accumulated benefit obligation, plans with ABO in excess of plan assets	(80,759)	(218,769)
Fair value of plan assets, plans with ABO in excess of plan assets	77,036	196,800
Plans with accumulated benefit obligation less than plan assets
Projected benefit obligation, plans with ABO less than plan assets	(145,052)	(12,161)
Accumulated benefit obligation, plans with ABO less than plan assets	(144,006)	(10,924)
Fair value of plan assets, plans with ABO less than plan assets	$ 147,676	$ 12,012