Financial Instruments - Effect of Derivative Instruments on Consolidated Statement of Operations and Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative	$ (0.2)	$ 0.7	$ 1.6	$ (0.7)
Interest rate contracts | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI Into Income	(0.7)	(0.8)	(1.5)	(1.3)
Make-whole derivative liability | Non-Operating Income (Expenses) – Net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	0.0	(102.6)	0.0	(32.8)
Foreign exchange collar | Non-Operating Income (Expenses) – Net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	0.0	0.0	(2.5)	0.0
Foreign exchange forward contracts | Non-Operating Income (Expenses) – Net
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ (1.4)	$ (1.2)	$ 1.5	$ (0.5)