Long-term Debt (Schedule of Long-term Debt) (Details) (USD $) In Thousands, unless otherwise specified			6 Months Ended	12 Months Ended		12 Months Ended											3 Months Ended								12 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013 2008 Term Loan [Member]	Sep. 30, 2012 2008 Term Loan [Member] Medium-term Notes [Member]	Sep. 30, 2013 2008 Term Loan [Member] Medium-term Notes [Member]	Sep. 30, 2013 Series B Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2012 Series B Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series C Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2012 Series C Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series D Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2012 Series D Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series E Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2012 Series E Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Series F Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2012 Series F Notes [Member] Notes Payable to Banks [Member]	Dec. 31, 2013 2013 Note Purchase Agreement [Member]	Dec. 31, 2013 Series J Notes [Member] Notes Payable to Banks [Member]	Dec. 31, 2013 Series G Notes [Member] Notes Payable to Banks [Member]	Dec. 31, 2013 Series H Notes [Member] Notes Payable to Banks [Member]	Dec. 31, 2013 Series I Notes [Member] Notes Payable to Banks [Member]	Dec. 31, 2013 Series K Notes [Member] Notes Payable to Banks [Member]	Dec. 31, 2013 Series L Notes [Member] Notes Payable to Banks [Member]	Sep. 30, 2013 Total Accumulated Other Comprehensive (Loss) Earnings [Member] Designated as Hedging Instrument [Member]	Sep. 30, 2012 Total Accumulated Other Comprehensive (Loss) Earnings [Member] Designated as Hedging Instrument [Member]	Sep. 30, 2013 Domestic Line Of Credit [Member]	Sep. 30, 2013 Domestic Line Of Credit [Member] Line Of Credit [Member]	Sep. 30, 2013 Chinese Credit Facility, RMB Denominated Loan [Member]	Sep. 30, 2013
Long-term debt balance	$ 550,000			$ 41,875	$ 0	$ 100,000	$ 100,000	$ 50,000	$ 50,000	$ 100,000	$ 100,000	$ 57,000	$ 57,000	$ 43,000	$ 43,000										$ 200,000
Fair value hedge adjustment for unrecognized discontinued hedge gains																							71	(607)
Variable interest rate				1.47%	0.00%
Debt Instrument, Description of Variable Rate Basis			LIBOR														LIBOR								prime rate or an adjusted LIBOR		prevailing interest rate offered by the People's Bank of China on the date of borrowing	lender's cost of borrowing rate at the date of borrowing
Basis Spread On Variable Rate																	1.25%										25.00%	3.00%
Interest rate						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																									1.06%	1.06%
Maturity date				Oct. 01, 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
Total long-term debt	550,000	391,875
Less: current portion	(100,000)	(7,500)
Long-term debt, less current portion	450,000	384,375
Debt Instrument, Face Amount																$ 250,000	$ 50,000	$ 50,000	$ 25,000	$ 25,000	$ 50,000	$ 50,000