Derivatives (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Fair Value, Net	$ (30,400,000)		$ (30,400,000)		$ 10,300,000
Cash Flow Hedging [Member] | Other Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Fair Value, Net					900,000
Cash Flow Hedging [Member] | Other Current Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Fair Value, Net	(49,800,000)		(49,800,000)		(7,700,000)
Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	13,600,000		13,600,000		6,700,000
Currency Swap [Member] | Other Current Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Fair Value, Net	(700,000)		(700,000)
Currency Swap [Member] | Other Current Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Fair Value, Net					200,000
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	155,400,000		155,400,000		76,700,000
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	500,000	$ 500,000	500,000
Derivative, Gain on Derivative	(100,000)		1,100,000
Derivative, Loss on Derivative		(1,300,000)		$ (1,600,000)
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	750,000,000.0		750,000,000.0		750,000,000.0
Net Investment Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Notional Amount	198,300,000		198,300,000
Net Investment Hedging [Member] | Other Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, Fair Value, Net	20,100,000		20,100,000		$ 16,900,000
Net Investment Hedging [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	$ 1,300,000	$ 1.3	$ 3,900,000	$ 3.9