Financial Instruments - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Jan. 08, 2021	Jun. 30, 2021	Dec. 31, 2020
Assets:
Cash equivalents		$ 2.4	$ 212.3
Foreign exchange forwards
Assets:
Derivative asset		0.5	2.0
Liabilities:
Derivative Liability		1.0	0.9
Foreign exchange collar
Assets:
Derivative asset			23.5
Swap arrangements
Assets:
Derivative asset		0.6
Liabilities:
Derivative Liability			1.0
Foreign Exchange Contract
Liabilities:
Realized gains on foreign exchange contracts	$ 21.0
Quoted Prices in Active Markets for Identical Assets (Level I)
Assets:
Cash equivalents		2.4	212.3
Quoted Prices in Active Markets for Identical Assets (Level I) | Foreign exchange forwards
Assets:
Derivative asset		0.0	0.0
Liabilities:
Derivative Liability		0.0	0.0
Quoted Prices in Active Markets for Identical Assets (Level I) | Foreign exchange collar
Assets:
Derivative asset			0.0
Quoted Prices in Active Markets for Identical Assets (Level I) | Swap arrangements
Assets:
Derivative asset		0.0
Liabilities:
Derivative Liability			0.0
Significant Other Observable Inputs (Level II)
Assets:
Cash equivalents		0.0	0.0
Significant Other Observable Inputs (Level II) | Foreign exchange forwards
Assets:
Derivative asset		0.5	2.0
Liabilities:
Derivative Liability		1.0	0.9
Significant Other Observable Inputs (Level II) | Foreign exchange collar
Assets:
Derivative asset			23.5
Significant Other Observable Inputs (Level II) | Swap arrangements
Assets:
Derivative asset		0.6
Liabilities:
Derivative Liability			1.0
Significant Unobservable Inputs (Level III)
Assets:
Cash equivalents		0.0	0.0
Significant Unobservable Inputs (Level III) | Foreign exchange forwards
Assets:
Derivative asset		0.0	0.0
Liabilities:
Derivative Liability		0.0	0.0
Significant Unobservable Inputs (Level III) | Foreign exchange collar
Assets:
Derivative asset			0.0
Significant Unobservable Inputs (Level III) | Swap arrangements
Assets:
Derivative asset		$ 0.0
Liabilities:
Derivative Liability			$ 0.0