Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 1,197.1	$ 1,333.5
Restricted cash	95.4	95.4
Short-term investment securities	105.9	106.3
Assets held for sale	2.5	2.5
Total assets	1,400.9	1,537.7
Derivative liability	40.2
Total liabilities	40.2	0.0
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	1,197.1	1,333.5
Restricted cash	95.4	95.4
Short-term investment securities	105.9	106.3
Assets held for sale	0.0	0.0
Total assets	1,398.4	1,535.2
Derivative liability	0.0
Total liabilities	0.0	0.0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0.0	0.0
Restricted cash	0.0	0.0
Short-term investment securities	0.0	0.0
Assets held for sale	0.0	0.0
Total assets	0.0	0.0
Derivative liability	40.2
Total liabilities	40.2	0.0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0.0	0.0
Restricted cash	0.0	0.0
Short-term investment securities	0.0	0.0
Assets held for sale	2.5	2.5
Total assets	2.5	2.5
Derivative liability	0.0
Total liabilities	$ 0.0	$ 0.0