Credit Facilities, Short-term Borrowings (Narrative) (Details) BRL in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2016 BRL	Sep. 30, 2016 USD ($)
Maximum borrowing capacity					$ 1,052,568
Accelerated amortization of debt financing costs recognized as interest expense	$ 1,165	$ 1,114	$ 1,014
Outstanding borrowings					156,700
Short-term borrowings		2,430			150,000
Line of Credit Facility, Remaining Borrowing Capacity					887,795
Additional borrowing availability					887,795
Long-term debt, excluding current portion		848,488			577,153
Amortization of Financing Costs	$ 1,165	$ 1,114	$ 1,014
Other Foreign Short-term Borrowings [Member]
Outstanding borrowings					0
Foreign Performance Guarantee Facilities [Member]
Maximum borrowing capacity					8,567
Outstanding borrowings					0
Line of Credit Facility, Remaining Borrowing Capacity					8,324
Additional borrowing availability					8,324
Foreign Lines of Credit And Overdraft Facilities [Member]
Maximum borrowing capacity					44,001
Outstanding borrowings					0
Line of Credit Facility, Remaining Borrowing Capacity					44,001
Additional borrowing availability					44,001
Revolving Credit Facility [Member]
Maximum borrowing capacity					1,000,000
Outstanding borrowings					156,700
Line of Credit Facility, Remaining Borrowing Capacity					835,470
Additional borrowing availability					835,470
Revolving Credit Agreement [Member]
Maximum borrowing capacity					1,000,000
Option to increase maximum borrowings to this amount					$ 1,200,000
Line of Credit Facility, Expiration Date	Apr. 01, 2020
Variable Rate Basis	LIBOR
Credit facility effective interest rate on outstanding borrowing		1.44%		1.77%	1.77%
Cross default provisions related to the Company’s other outstanding debt arrangements in excess of this amount, the occurrence of which would permit the lenders to accelerate the amounts due thereunder					$ 60,000
Debt Covenant, Minimum Consolidated Net Worth Calculation, Base Value					$ 800,000
Debt Covenant, Minimum Consolidated Net Worth Calculation, Percentage of Net Income				50.00%	50.00%
Debt Covenant, Minimum Consolidated Net Worth Calculation, Percentage of Net Proceeds of Issuance of Capital Stock				50.00%	50.00%
Debt Covenant, Leverage Ratio, Maximum	3.5
Debt Covenant, Leverage Ratio During Material Acquisition Period, Maximum	4.0
Debt Covenant, Leverage Ratio Next Two Succeeding Fiscal Quarters Following Material Acquisition, Maximum	3.75
Outstanding borrowings		$ 350,000			$ 156,700
Current portion of outstanding borrowings	$ 150,000
Revolving Credit Agreement [Member] | Minimum [Member]
Basis Spread On Variable Rate	0.85%
Revolving Credit Agreement [Member] | Maximum [Member]
Basis Spread On Variable Rate	1.65%
Chinese Credit Facility [Member]
Maximum borrowing capacity					22,700
Line of Credit Facility, Expiration Date	Nov. 30, 2016
Outstanding borrowings					0
Chinese Credit Facility, RMB Denominated Loan [Member]
Variable Rate Basis	interest at the prevailing interest rate offered by the People's Bank of China on the date of borrowing, plus a margin equal to 15% of that prevailing rate
Chinese Credit Facility, USD Denominated Loan [Member]
Variable Rate Basis	interest at the lender's cost of borrowing rate at the date of borrowing, plus 3%
Brazil Credit Facility [Member]
Line of Credit Facility, Expiration Date	Jan. 16, 2017
Brazil Credit Facility BRL Denominated Loan [Member]
Maximum borrowing capacity | BRL				BRL 52,000
Variable Rate Basis	interest at the lender's cost of borrowing rate at the date of borrowing, plus 1.75%
Outstanding borrowings		$ 2,430			$ 0
The Notes [Member]
Debt Covenant, Leverage Ratio, Maximum	3.5
Debt Covenant, Leverage Ratio During Material Acquisition Period, Maximum	4.0