Long-term Debt (Schedule of Long-term Debt) (Details) (USD $) In Thousands, unless otherwise specified			9 Months Ended		9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended		9 Months Ended		3 Months Ended				9 Months Ended				9 Months Ended
	Jun. 30, 2014	Sep. 30, 2013	Jun. 30, 2014 Domestic Line Of Credit [Member]	Sep. 30, 2013 Domestic Line Of Credit [Member]	Jun. 30, 2014 Series B Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series B Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series C Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series C Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series D Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series D Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series E Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series E Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series F Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series F Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series J Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series J Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series G Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series G Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series H Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series H Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series I Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series I Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series K Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series K Notes [Member] Notes Payable to Banks [Member]	Jun. 30, 2014 Series L Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series L Notes [Member] Notes Payable to Banks [Member]	Dec. 31, 2013 Domestic Line Of Credit [Member]	Jun. 30, 2014 Domestic Line Of Credit [Member]	Sep. 30, 2013 Domestic Line Of Credit [Member]	Jun. 30, 2014 Revolving Credit Facility [Member]	Jun. 30, 2014 Revolving Credit Facility [Member] Minimum [Member]	Jun. 30, 2014 Revolving Credit Facility [Member] Maximum [Member]	Jun. 30, 2014 Revolving Credit Agreement [Member]	Sep. 30, 2013 Revolving Credit Agreement [Member]	Jun. 30, 2014 Chinese Credit Facility, RMB Denominated Loan [Member]	Jun. 30, 2014
Long-term debt balance					$ 0	$ 100,000	$ 50,000	$ 50,000	$ 100,000	$ 100,000	$ 57,000	$ 57,000	$ 43,000	$ 43,000	$ 50,000	$ 0	$ 50,000	$ 0	$ 25,000	$ 0	$ 25,000	$ 0	$ 50,000	$ 0	$ 50,000	$ 0		$ 0	$ 200,000				$ 165,000	$ 0
Debt Instrument, Description of Variable Rate Basis															LIBOR												prime rate or an adjusted LIBOR						LIBOR		interest at the prevailing interest rate offered by the People's Bank of China on the date of borrowing, plus a margin equal to 25% of that prevailing rate	interest at the lender's cost of borrowing rate at the date of borrowing, plus 3%
Basis Spread On Variable Rate															1.25%																0.85%	1.65%
Interest rate				1.06%	5.63%	5.63%	5.92%	5.92%	6.39%	6.39%	7.81%	7.81%	8.24%	8.24%			3.42%		4.03%		4.18%		4.03%		4.18%
Credit facility effective interest rate on outstanding borrowing																														1.20%
Maturity date			Dec. 20, 2013		Oct. 01, 2013	Oct. 01, 2013	Oct. 01, 2015	Oct. 01, 2015	Oct. 01, 2018	Oct. 01, 2018	Apr. 03, 2016	Apr. 03, 2016	Apr. 03, 2019	Apr. 03, 2019	Nov. 15, 2020		Nov. 15, 2020		Nov. 15, 2023		Nov. 15, 2025		Nov. 15, 2023		Nov. 15, 2025								Jul. 01, 2018
Total debt	665,000	550,000
Current portion of long-term debt	0	(100,000)
Long-term debt, excluding current portion	$ 665,000	$ 450,000