Derivative Instruments and Hedging Activities (Impact of Derivative Instruments on Earnings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments Gain Loss [Line Items]
Amount of (Income) Expense Recognized in Earnings on Derivative	$ 33,224	$ (68,880)	$ (3,702)
Amount of (Gain) Loss Recognized in Accumulated OCI on Derivative	36,587	(89,048)	1,672
Amount of (Gain) Loss Reclassified from Accumulated OCI into Earnings	33,224	(68,880)	(3,702)
Floating-Rate Cross Currency Interest Rate Contract [Member] | Derivatives in Fair Value Hedging Relationships [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of (Income) Expense Recognized in Earnings on Derivative	$ 939	$ (2,844)	$ 23
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Selling, general and administrative expenses	Selling, general and administrative expenses	Selling, general and administrative expenses
Amount of (Gain) Loss Recognized in Accumulated OCI on Derivative	$ 875	$ (2,854)	$ 60
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Selling, general and administrative expenses	Selling, general and administrative expenses	Selling, general and administrative expenses
Amount of (Gain) Loss Reclassified from Accumulated OCI into Earnings	$ 939	$ (2,844)	$ 23
Fixed-Rate Cross Currency Interest Rate Contract [Member] | Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Amount of (Income) Expense Recognized in Earnings on Derivative	$ 32,285	$ (66,036)	$ (3,725)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Selling, general and administrative expenses	Selling, general and administrative expenses	Selling, general and administrative expenses
Amount of (Gain) Loss Recognized in Accumulated OCI on Derivative	$ 35,712	$ (86,194)	$ 1,612
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration]	Selling, general and administrative expenses	Selling, general and administrative expenses	Selling, general and administrative expenses
Amount of (Gain) Loss Reclassified from Accumulated OCI into Earnings	$ 32,285	$ (66,036)	$ (3,725)