Derivative Instruments - Derivative Narrative (Details) - Designated as Hedging Instrument [Member] - Cross Currency Interest Rate Contract [Member] - Net Investment Hedging [Member] - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2020
Derivative [Line Items]
Derivative, Cash Received on Hedge	$ 1.1
October 2018 cross currency swap [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 100.0
Derivative, Fixed Interest Rate		2.90%
November 2020 cross currency swap [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 50.0
Derivative, Fixed Interest Rate		0.80%
Maximum [Member] | October 2018 cross currency swap [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 125.0
Maximum [Member] | November 2020 cross currency swap [Member]
Derivative [Line Items]
Derivative, Notional Amount		50.0
Minimum [Member] | October 2018 cross currency swap [Member]
Derivative [Line Items]
Derivative, Notional Amount		75.0
Minimum [Member] | November 2020 cross currency swap [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 25.0