Derivative Instruments | Net Investment Hedge Notional Amounts (Details) $ in Millions	Apr. 30, 2019 USD ($)
Maturity Year One [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 4.6
Maturity Year Two [Member]
Derivative [Line Items]
Derivative, Notional Amount	9.3
Maturity Year Three [Member]
Derivative [Line Items]
Derivative, Notional Amount	9.3
Maturity Year Four [Member]
Derivative [Line Items]
Derivative, Notional Amount	254.6
Net Investment Hedging [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 277.8