Derivative Financial Instruments - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - Designated as Hedging Instrument - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Assets	$ 1.0	$ 3.5
Liabilities	(2.5)	(4.2)
Net Investment Hedging | Forward foreign currency contracts
Derivative [Line Items]
Assets	1.0	3.5
Liabilities	(1.4)	(2.3)
Cash Flow Hedging | Interest rate swap
Derivative [Line Items]
Assets	0.0	0.0
Liabilities	$ (1.1)	$ (1.9)