Derivative Instruments and Hedging Activities (Narrative) (Details) $ in Thousands			1 Months Ended		12 Months Ended
	May 30, 2018 USD ($)	Apr. 18, 2018 USD ($)	Jul. 31, 2017 USD ($)	Aug. 31, 2013 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Jun. 01, 2018 EUR (€)	May 31, 2018 USD ($) loan	Sep. 23, 2016 EUR (€)	Jul. 31, 2016 USD ($)	Jun. 30, 2013 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain recognized in accumulated OCI on derivative					$ 47,759	$ (23,000)
Term of gain or loss recognition in interest expense on terminated derivatives recorded in OCI					12 months
Derivative, cost of hedge						5,543
First China Intercompany Loan [Member]
Derivative Instruments, Gain (Loss) [Line Items]
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			$ 380				$ 453
Total Accumulated Other Comprehensive (Loss) Earnings [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Remaining unrecognzied gains (losses) associated with derivative instruments included in AOCI					$ 5,004	(21,315)
Fixed-Rate Cross Currency Interest Rate Contract [Member] | Designated as Hedging Instrument [Member] | Derivatives in Cash Flow Hedging Relationships [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, number of instruments | loan									5
Derivative, notional amount									$ 400,000
Fixed-Rate Cross Currency Interest Rate Contract [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount									400,000
Floating-Rate Cross Currency Interest Rate Contract [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount									$ 167,420
Treasury Lock [Member] | Designated as Hedging Instrument [Member] | Derivatives in Cash Flow Hedging Relationships [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain recognized in accumulated OCI on derivative				$ 507
Net unrecognized gains on terminated derivative instruments expected to be reclassified to earnings					$ 72
Derivative, notional amount												$ 25,000
Foreign Exchange Option [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount | €								€ 490,000,000
Derivative, exchange rate	1.2432							1.2432
Derivative, currency bought					Euro
Derivative, cost of hedge	$ 5,543	$ 5,543
2016 Note Purchase Agreements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Issuance date					Sep. 23, 2016
Face amount | €										€ 160,000,000
Series O Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Face amount | €										43,000,000
Series N Notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Face amount | €										77,000,000
Series M Notes [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					$ 2,682	$ 838	$ (2,395)
Face amount | €										€ 40,000,000