Credit Facilities and Short-term Borrowings (Short-term Borrowings and Availability Under Various Short-term Credit Facilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Line of Credit Facility [Line Items]
Total availability	$ 1,012,858
Outstanding letters of credit and guarantees	(13,020)
Outstanding borrowings	(270,176)
Remaining availability	729,662
Other Foreign Short-term Borrowings [Member]
Line of Credit Facility [Line Items]
Total availability	3,635
Outstanding borrowings	(3,635)	$ 0
Foreign Performance Guarantee Facilities [Member]
Line of Credit Facility [Line Items]
Total availability	1,783
Outstanding letters of credit and guarantees	(1,536)
Remaining availability	247
Foreign Lines of Credit And Overdraft Facilities [Member]
Line of Credit Facility [Line Items]
Total availability	7,440
Outstanding borrowings	0
Remaining availability	7,440
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Total availability	1,000,000
Outstanding letters of credit and guarantees	(11,484)
Outstanding borrowings	(266,541)
Remaining availability	$ 721,975