Credit Facilities, Short-term Borrowings (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Maximum borrowing capacity	$ 1,048,808
Debt Covenant, Leverage Ratio, Maximum	3.5 to 1.0
Accelerated amortization of debt financing costs recognized as interest expense	$ 1,114	$ 1,014	$ 1,045
Outstanding borrowings	352,430
Short-term borrowings	2,430	0
Line of Credit Facility, Remaining Borrowing Capacity	687,758
Additional borrowing availability	687,758
Long-term debt, excluding current portion	850,000	710,000
Amortization of Financing Costs	1,114	$ 1,014	$ 1,045
Other Foreign Short-term Borrowings [Member]
Outstanding borrowings	0
Foreign Performance Guarantee Facilities [Member]
Maximum borrowing capacity	8,619
Outstanding borrowings	0
Line of Credit Facility, Remaining Borrowing Capacity	8,276
Additional borrowing availability	8,276
Foreign Lines of Credit And Overdraft Facilities [Member]
Maximum borrowing capacity	40,189
Outstanding borrowings	2,430
Line of Credit Facility, Remaining Borrowing Capacity	37,759
Additional borrowing availability	37,759
Revolving Credit Facility [Member]
Maximum borrowing capacity	1,000,000
Outstanding borrowings	350,000
Line of Credit Facility, Remaining Borrowing Capacity	641,723
Additional borrowing availability	$ 641,723
Revolving Credit Facility [Member] | Minimum [Member]
Basis Spread On Variable Rate	0.85%
The Notes [Member]
Debt Covenant, Minimum Consolidated Net Worth Calculation, Base Value	$ 800,000
Debt Covenant, Minimum Consolidated Net Worth Calculation, Percentage of Net Income	50.00%
Debt Covenant, Leverage Ratio During Material Acquisition Period, Maximum	4.0 to 1.0
Amended Revolving Credit Agreement [Member]
Variable Rate Basis	LIBOR