Derivative Instruments (Details) In Thousands, unless otherwise specified	3 Months Ended				12 Months Ended			3 Months Ended			3 Months Ended
	Sep. 30, 2013 Foreign Exchange Forward and Option contracts [Member] Foreign Exchange (Loss) Gain [Member] USD ($)	Sep. 30, 2012 Foreign Exchange Forward and Option contracts [Member] Foreign Exchange (Loss) Gain [Member] USD ($)	Sep. 30, 2013 Power Hedges [Member] Cost of Goods Sold [Member] USD ($)	Sep. 30, 2012 Power Hedges [Member] Cost of Goods Sold [Member] USD ($)	Jun. 30, 2010 Power Hedge October 2010 [Member] MWh	Sep. 30, 2013 Foreign Exchange Forward Contracts [Member] USD ($)	Sep. 30, 2013 Foreign Exchange Forward Contracts [Member] EUR (€)	Sep. 30, 2013 Foreign Exchange Forward Contracts [Member] Maximum [Member]	Sep. 30, 2013 Foreign Exchange Forward Contracts [Member] Minimum [Member]	Sep. 30, 2013 Foreign Exchange Forward Contracts [Member] Euro [Member]	Sep. 30, 2013 Foreign Exchange Option Contracts [Member] USD ($)	Sep. 30, 2013 Foreign Exchange Option Contracts [Member] EUR (€)	Sep. 30, 2013 Foreign Exchange Option Contracts [Member] Canadian Dollar [Member]	Sep. 30, 2013 Foreign Exchange Option Contracts [Member] Euro [Member]
Derivative [Line Items]
Notional value							€ 5,075					€ 2,000
Average forward exchange rate						1.33	1.33			1.00			1.35	1.00
Expiration date of agreement					Jun. 30, 2013			Nov. 30, 2013	Oct. 31, 2013		Oct. 31, 2013	Oct. 31, 2013
Notional amount of electricity supplied per agreement (in MWh)					87,600
Asset included in prepaid expenses and other current assets											1
Liability included in accrued expenses and other current liabilities						142
Fixed power rate, price per MWh					39.95
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized	$ (427)	$ 71	$ 0	$ 261