Retirement Benefits (Schedule of Changes in accumulated other comprehensive losses for the defined benefit plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Net (gain) loss arising during the period	$ (22,979)	$ 19,718	$ 26,866
Loss (gain) due to settlement or curtailment arising during the period		(47)
Amortization of: Net gains (losses)	(2,570)	(1,694)	(513)
Amortization of: Prior service benefit (cost)	3,470	(226)	(225)
Foreign currency exchange rate changes	43	(2,239)	(867)
Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss (earnings), beginning of year	58,334	44,720
Net (gain) loss arising during the period	(20,930)	17,806
Loss (gain) due to settlement or curtailment arising during the period	0	(47)
Amortization of: Net gains (losses)	(2,369)	(1,538)
Amortization of: Prior service benefit (cost)	3,312	(384)
Foreign currency exchange rate changes	43	(2,223)
Accumulated other comprehensive loss (earning), end of year	38,390	58,334	44,720
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss (earnings), beginning of year	5,166	3,268
Net (gain) loss arising during the period	(2,049)	1,912
Amortization of: Net gains (losses)	(201)	(156)
Amortization of: Prior service benefit (cost)	158	158
Foreign currency exchange rate changes	0	(16)
Accumulated other comprehensive loss (earning), end of year	3,074	5,166	3,268
UNITED STATES | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss (earnings), beginning of year	37,539	31,102
Net (gain) loss arising during the period	(14,805)	8,160
Loss (gain) due to settlement or curtailment arising during the period	0	(47)
Amortization of: Net gains (losses)	(1,854)	(1,292)
Amortization of: Prior service benefit (cost)	3,312	(384)
Foreign currency exchange rate changes	0	0
Accumulated other comprehensive loss (earning), end of year	24,192	37,539	31,102
Foreign Plan [Member] | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss (earnings), beginning of year	20,795	13,618
Net (gain) loss arising during the period	(6,125)	9,646
Loss (gain) due to settlement or curtailment arising during the period	0	0
Amortization of: Net gains (losses)	(515)	(246)
Amortization of: Prior service benefit (cost)	0	0
Foreign currency exchange rate changes	43	(2,223)
Accumulated other comprehensive loss (earning), end of year	$ 14,198	$ 20,795	$ 13,618