Goodwill and Identifiable Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Intangible assets subject to amortization:
Other Finite-Lived Intangible Assets, Gross	$ 674.6	$ 674.6
Accumulated Amortization	413.9	377.8
Net Carrying Amount	260.7	296.8
Intangible assets not subject to amortization:
Trademarks, Carrying Amount	272.8	272.8
Intangible Assets, Gross (Excluding Goodwill)	947.4	947.4
Intangible Assets, Net (Excluding Goodwill), Total	533.5	569.6
Customer and Contractual Relationships
Intangible assets subject to amortization:
Other Finite-Lived Intangible Assets, Gross	589.3	589.3
Accumulated Amortization	345.6	315.7
Net Carrying Amount	$ 243.7	273.6
Customer and Contractual Relationships | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Customer and Contractual Relationships | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	13 years
Backlog
Intangible assets subject to amortization:
Other Finite-Lived Intangible Assets, Gross	$ 44.1	44.1
Accumulated Amortization	40.3	36.5
Net Carrying Amount	$ 3.8	7.6
Backlog | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Backlog | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	3 years
Noncompete Agreements
Intangible assets subject to amortization:
Other Finite-Lived Intangible Assets, Gross	$ 41.2	41.2
Accumulated Amortization	28.0	25.6
Net Carrying Amount	$ 13.2	$ 15.6
Noncompete Agreements | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Noncompete Agreements | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years