Long-term Debt (Narrative) (Details) € in Thousands, $ in Thousands			3 Months Ended	12 Months Ended
	Apr. 04, 2016 USD ($)	Oct. 01, 2015 USD ($)	Dec. 31, 2015	Sep. 30, 2016 EUR (€)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2016 USD ($)	Apr. 28, 2015 USD ($)
Debt financing costs					$ 863	$ 2,359	$ 1,297
Amortization of debt financing costs recognized as interest expense					$ 1,165	1,114	1,014
Balance of unamortized debt issuance costs						1,512		$ 2,091
Line of Credit Facility, Maximum Borrowing Capacity								1,052,568
Outstanding borrowings								156,700
The Notes [Member]
Debt Covenant, Leverage Ratio, Maximum				3.5	3.5
Debt Covenant, Calculations, Period Of Time				rolling four quarter basis	rolling four quarter basis
Debt Covenant, Leverage Ratio During Material Acquisition Period, Maximum				4.0	4.0
Prepayment, Maximum Percentage of Principal				100.00%	100.00%
Balance of unamortized debt issuance costs						1,512		2,091
The USD 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%				50.00%
Debt Covenant, Maximum Percentage of Priority Debt To Consolidated Net Worth				25.00%	25.00%
Prepayment, Partial Payment Minimum					$ 1,000
Non Floating Rate Notes [Member]
Prepayment, Make-Whole Amount Computation, Discount Rate Basis Points				50	50
Debt Instrument Prepayment Make Whole Amount Computation				computed by discounting the remaining scheduled payments of interest and principal of the USD Notes being prepaid at a discount rate equal to the sum of 50 basis points and the yield to maturity of U.S. Treasury securities having a maturity equal to the remaining average life of the USD Notes being prepaid	computed by discounting the remaining scheduled payments of interest and principal of the USD Notes being prepaid at a discount rate equal to the sum of 50 basis points and the yield to maturity of U.S. Treasury securities having a maturity equal to the remaining average life of the USD Notes being prepaid
2008 Note Purchase Agreement [Member]
Issuance Date				Oct. 01, 2008	Oct. 01, 2008
Series C Notes [Member]
Principal Payment Amount		$ 50,000
2009 Note Purchase Agreement [Member]
Issuance Date				Apr. 01, 2009	Apr. 01, 2009
Series E Notes [Member]
Principal Payment Amount	$ 57,000
2013 Note Purchase Agreement [Member]
Issuance Date				Oct. 01, 2013	Oct. 01, 2013
Face Amount								$ 250,000
Debt financing costs							$ 1,297
Floating Rate Notes [Member]
Debt Instrument Prepayment Make Whole Amount Computation				computed as a percentage of the principal amount of the Series J Notes equal to (a) 2%, on or prior to November 15, 2014, (b) 1%, after November 15, 2014 and on or prior to November 15, 2015, and (c) 0% after November 15, 2015	computed as a percentage of the principal amount of the Series J Notes equal to (a) 2%, on or prior to November 15, 2014, (b) 1%, after November 15, 2014 and on or prior to November 15, 2015, and (c) 0% after November 15, 2015
Series J Notes [Member]
Variable interest rate				2.06%				2.06%
First Closing Notes [Member]
Issuance Date				Oct. 01, 2013	Oct. 01, 2013
Second Closing Notes [Member]
Issuance Date			Nov. 15, 2013	Nov. 15, 2013	Nov. 15, 2013
2016 Note Purchase Agreements [Member]
Issuance Date				Sep. 23, 2016	Sep. 23, 2016
Face Amount | €				€ 160,000
Debt Covenant, Minimum Consolidated Net Worth Calculation, Base Value								$ 1,046,619
Debt Covenant, Minimum Consolidated Net Worth Calculation, Percentage of Net Income				50.00%				50.00%
Prepayment, Partial Payment Minimum | €				€ 1,000
Debt financing costs					$ 863
2016 Notes Subject to Swap Agreement [Member]
Debt Instrument Prepayment Make Whole Amount Computation				adjusted for theoretical holder returns foregone on hypothetical reinvestments in U.S. Treasury securities (the "Swapped Notes") is equal to the excess of an amount equal to the remaining scheduled payments to be paid in respect of such called principal under such swap agreement discounted at a rate equal to 50 basis points and the yield to maturity of U.S. Treasury securities having a maturity equal to the remaining average life of the Swapped Notes being prepaid over the amount of payments in U.S. dollars that would be paid to the holder of the Swapped Note in respect of the called principal under the swap agreement, which amount will be increased or reduced, as applicable, in an amount equal to any net gain or loss realized by the holder of such Swapped Note on swap transactions under such swap agreement as a result of such prepayment.	adjusted for theoretical holder returns foregone on hypothetical reinvestments in U.S. Treasury securities (the "Swapped Notes") is equal to the excess of an amount equal to the remaining scheduled payments to be paid in respect of such called principal under such swap agreement discounted at a rate equal to 50 basis points and the yield to maturity of U.S. Treasury securities having a maturity equal to the remaining average life of the Swapped Notes being prepaid over the amount of payments in U.S. dollars that would be paid to the holder of the Swapped Note in respect of the called principal under the swap agreement, which amount will be increased or reduced, as applicable, in an amount equal to any net gain or loss realized by the holder of such Swapped Note on swap transactions under such swap agreement as a result of such prepayment.
2016 Notes Not Subject to Swap Agreement [Member]
Debt Instrument Prepayment Make Whole Amount Computation				computed by discounting the remaining scheduled payments of interest and principal of such notes being prepaid at a discount rate equal to the sum of 50 basis points and the yield to maturity of the German Bund having a maturity equal to the remaining average life of the 2016 Notes being prepaid	computed by discounting the remaining scheduled payments of interest and principal of such notes being prepaid at a discount rate equal to the sum of 50 basis points and the yield to maturity of the German Bund having a maturity equal to the remaining average life of the 2016 Notes being prepaid
Series M Notes [Member]
Face Amount | €				€ 40,000
Series N Notes [Member]
Face Amount | €				77,000
Series O Notes [Member]
Face Amount | €				€ 43,000
Revolving Credit Facility [Member]
Balance of unamortized debt issuance costs									$ 2,014
Other Foreign Short-term Borrowings [Member]
Outstanding borrowings								$ 0
Foreign Performance Guarantee Facilities [Member]
Line of Credit Facility, Maximum Borrowing Capacity								8,567
Outstanding borrowings								0
Foreign Lines of Credit And Overdraft Facilities [Member]
Line of Credit Facility, Maximum Borrowing Capacity								44,001
Outstanding borrowings								0
Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity								1,000,000
Outstanding borrowings								156,700
Chinese Credit Facility [Member]
Line of Credit Facility, Expiration Date				Nov. 30, 2016	Nov. 30, 2016
Line of Credit Facility, Maximum Borrowing Capacity								22,700
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	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%	interest at the lender's cost of borrowing rate at the date of borrowing, plus 3%
Revolving Credit Agreement [Member]
Variable Rate Basis				LIBOR	LIBOR
Debt Covenant, Leverage Ratio, Maximum				3.5	3.5
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 During Material Acquisition Period, Maximum				4.0	4.0
Line of Credit Facility, Expiration Date				Apr. 01, 2020	Apr. 01, 2020
Line of Credit Facility, Maximum Borrowing Capacity								$ 1,000,000
Outstanding borrowings						$ 350,000		$ 156,700
Credit facility effective interest rate on outstanding borrowing				1.77%		1.44%		1.77%
Revolving Credit Agreement [Member] | Minimum [Member]
Basis Spread On Variable Rate				0.85%	0.85%
Revolving Credit Agreement [Member] | Maximum [Member]
Basis Spread On Variable Rate				1.65%	1.65%