Derivative Instruments and Hedging Activities (Narrative) (Details) € in Thousands, ¥ in Thousands, $ in Thousands	3 Months Ended	12 Months Ended				15 Months Ended	18 Months Ended
	Sep. 30, 2013 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2013	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 EUR (€)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 CNY (¥)	Jun. 30, 2016 CNY (¥)	Jun. 30, 2013 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Net unrecognized gains on terminated derivative instruments expected to be reclassified to earnings		$ 72
Term of gain or loss recognition in interest expense on terminated derivatives recorded in OCI		12 months
EUR Denominated Loan [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on foreign currency transaction designated as a hedge of a net investment in a foreign subsidiary		$ (2,395)	$ (47)
First China Intercompany Loan [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on foreign currency transaction designated as a hedge of a net investment in a foreign subsidiary			912	$ 572			$ 1,484
Value of Net Investment Hedging Instruments Used | ¥											¥ 160,000
Second China Intercompany Loan [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on foreign currency transaction designated as a hedge of a net investment in a foreign subsidiary		$ 453	(73)			$ 380
Value of Net Investment Hedging Instruments Used | ¥										¥ 160,000
Derivatives in Cash Flow Hedging Relationships [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Term of gain or loss recognition in interest expense on terminated derivatives recorded in OCI					7 years
Derivative, Notional Amount												$ 25,000
Interest Expense [Member] | Derivatives in Cash Flow Hedging Relationships [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Accumulated OCI on Derivative	$ 507
Total Accumulated Other Comprehensive (Loss) Earnings [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrecognized gains (loss)			$ 290				$ 290		$ 218
2008 Note Purchase Agreement [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Issuance Date		Oct. 01, 2008
2009 Note Purchase Agreement [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Issuance Date		Apr. 01, 2009
2013 Note Purchase Agreement [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Issuance Date		Oct. 01, 2013
Face Amount									$ 250,000
First Closing Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Issuance Date		Oct. 01, 2013
Second Closing Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Issuance Date		Nov. 15, 2013
2016 Note Purchase Agreements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Issuance Date		Sep. 23, 2016
Face Amount | €								€ 160,000
Series M Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Value of Net Investment Hedging Instruments Used | €								40,000
Face Amount | €								40,000
Series N Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Face Amount | €								77,000
Series O Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Face Amount | €								€ 43,000