Goodwill and Identifiable Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Intangible assets subject to amortization:
Other Finite-Lived Intangible Assets, Gross	$ 525.3	$ 525.3
Accumulated Amortization	315.3	300.2
Net Carrying Amount	210.0	225.1
Intangible assets not subject to amortization:
Trademarks, Carrying Amount	272.8	272.8
Intangible Assets, Gross (Excluding Goodwill)	798.1	798.1
Identifiable intangible assets, net	482.8	497.9
Customer and Contractual Relationships
Intangible assets subject to amortization:
Other Finite-Lived Intangible Assets, Gross	496.0	496.0
Accumulated Amortization	296.0	282.0
Net Carrying Amount	$ 200.0	214.0
Customer and Contractual Relationships | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
Customer and Contractual Relationships | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	13 years
Backlog | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years
Backlog | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
Noncompete Agreements
Intangible assets subject to amortization:
Other Finite-Lived Intangible Assets, Gross	$ 29.3	29.3
Accumulated Amortization	19.3	18.2
Net Carrying Amount	$ 10.0	$ 11.1