Financial Instruments, Hedging Activities and Fair Value Measurements - Accumulated Other Comprehensive (Loss) Income (Details) - Fair Value, Inputs, Level 2 - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total AOCI	$ 38.6	$ 98.1
Cash flow hedging | Interest rate caps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total AOCI	0.7	2.6
Cash flow hedging | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total AOCI	38.6	60.0
Cash flow hedging | Foreign currency forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total AOCI	0.1	0.3
Net investment hedging | Cross-currency swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total AOCI	$ (0.8)	$ 35.2