Financial Instruments - Effect of Derivative Instruments on Consolidated Statement of Operations and Comprehensive Income (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 07, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI Into Income	$ 0.0	$ (2.8)	$ (0.7)	$ (0.9)
Amount of Gain (Loss) Recognized in Income on Derivatives	0.0	(2.8)	(0.7)	(0.9)
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative	0.0	0.9	(1.6)	(0.4)
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	(32.8)	(172.4)	0.0
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	23.5	0.0	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	$ 1.8	$ 9.5	$ (11.1)	$ (6.0)