Fair Value - Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Assets and Liabilities Measured at fair value on a recurring basis
Restricted cash	$ 7.2	$ 9.1
Fair Value, Recurring
Assets and Liabilities Measured at fair value on a recurring basis
Restricted cash	7.2	9.1
Short-term investments	41.8	39.2
Interest rate swap contracts		3.1
Foreign currency forward contracts	2.5	4.5
Total assets	419.4	387.5
Foreign currency forward contracts	24.1	19.8
Total liabilities	24.1	19.8
Fair Value, Recurring | Level 1, 2 and 3
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents	327.9	292.1
Fair Value, Recurring | Level 1
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents	327.8	289.3
Restricted cash	7.2	9.1
Short-term investments	0.0	0.0
Interest rate swap contracts		0.0
Foreign currency forward contracts	0.0	0.0
Total assets	335.0	298.4
Foreign currency forward contracts	0.0	0.0
Total liabilities	0.0	0.0
Fair Value, Recurring | Level 2
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents	0.1	2.8
Restricted cash	0.0	0.0
Short-term investments	41.8	39.2
Interest rate swap contracts		3.1
Foreign currency forward contracts	2.5	4.5
Total assets	44.4	49.6
Foreign currency forward contracts	24.1	19.8
Total liabilities	24.1	19.8
Fair Value, Recurring | Level 3
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents	0.0	0.0
Restricted cash	0.0	0.0
Short-term investments	0.0	0.0
Interest rate swap contracts		0.0
Foreign currency forward contracts	0.0	0.0
Total assets	0.0	0.0
Foreign currency forward contracts	0.0	0.0
Total liabilities	0.0	0.0
Fair Value, Recurring | Fair Value Measured at Net Asset Value Per Share
Assets and Liabilities Measured at fair value on a recurring basis
Cash and cash equivalents	$ 40.0	$ 39.5