Derivative Instruments and Hedging Activities (Narrative) (Details) $ in Thousands	1 Months Ended	12 Months Ended
	May 31, 2020 USD ($)	Sep. 30, 2021 USD ($) Swap loan	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2021 EUR (€) Swap loan	May 31, 2018 USD ($) loan	Sep. 23, 2016 EUR (€)
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount		$ 26,250
Proceed from net interest accrued on swap contracts settlement		526,715	$ 546,346
Amount of (Gain) Loss Reclassified from Accumulated OCI into Earnings		3,702	(2,134)	$ 31,446
Remaining unrecognized gains (losses) associated with derivative instruments included in AOCI		$ (26,506)	(21,132)
2016 Note Purchase Agreements [Member]
Derivative Instruments Gain Loss [Line Items]
Issuance date		Sep. 23, 2016
Face amount | €					€ 160,000,000		€ 160,000,000
Series M Notes [Member]
Derivative Instruments Gain Loss [Line Items]
Face amount | €					€ 40,000,000		€ 40,000,000
Maturity date		Sep. 23, 2026
Gain (Loss) on foreign currency transaction designated as a hedge of a net investment in a foreign subsidiary		$ 592	(3,199)	2,682
Floating-Rate Cross Currency Interest Rate Contract [Member] | Selling, General and Administrative Expense [Member] | Derivatives in Fair Value Hedging Relationships [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of (Gain) Loss Reclassified from Accumulated OCI into Earnings		(23)	(5,396)	8,356
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
Floating-Rate Cross Currency Interest Rate Contract [Member] | Designated as Hedging Instrument | Derivatives in Fair Value Hedging Relationships [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of (Gain) Loss Reclassified from Accumulated OCI into Earnings	$ 1,719
2020 Fixed-Rate Cross-Currency Swaps [Member]
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount		$ 400,000
2020 Fixed-Rate Cross-Currency Swaps [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount						400,000
Derivative, number of instruments | Swap		5			5
Floating Rate Cross Currency Swap [Member]
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount	108,823
Fixed Rate Cross Currency Swap [Member]
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount	400,000
Floating-Rate Cross-Currency Swap and Fixed-Rate Cross-Currency Swap [Member]
Derivative Instruments Gain Loss [Line Items]
Proceeds from swap contracts settlement	59,571
Derivative asset, fair value	58,191
Proceed from net interest accrued on swap contracts settlement	4,380
Floating-Rate Cross-Currency Swap and Fixed-Rate Cross-Currency Swap [Member] | Selling, General and Administrative Expense [Member]
Derivative Instruments Gain Loss [Line Items]
Swap termination fee	3,000
2020 Floating-Rate Cross-Currency Swap [Member]
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount		$ 45,000
Fixed-Rate Cross Currency Interest Rate Contract [Member] | Selling, General and Administrative Expense [Member] | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Amount of (Gain) Loss Reclassified from Accumulated OCI into Earnings		$ 3,725	$ 3,190	$ 23,018
Fixed-Rate Cross Currency Interest Rate Contract [Member] | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative, notional amount						$ 400,000
Derivative, number of instruments | loan		5			5	5
Amount of (Gain) Loss Reclassified from Accumulated OCI into Earnings	$ 32,200