Goodwill and Identifiable Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Millions		3 Months Ended
	Apr. 02, 2018	Mar. 31, 2019	Dec. 31, 2018
Intangible assets subject to amortization:
Gross Carrying Amount		$ 501.0	$ 483.5
Accumulated Amortization		269.7	257.0
Net Carrying Amount		231.3	226.5
Intangible assets not subject to amortization:
Trademarks, Carrying Amount		262.1	262.2
Intangible Assets, Gross (Excluding Goodwill)		763.1	745.7
Intangible Assets, Net (Excluding Goodwill)		493.4	488.7
Customer and Contractual Relationships
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	12 years 9 months
Intangible assets subject to amortization:
Gross Carrying Amount		362.4	346.9
Accumulated Amortization		153.8	145.4
Net Carrying Amount		$ 208.6	201.5
Customer and Contractual Relationships | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		2 months
Customer and Contractual Relationships | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		12 years 9 months
Contractor Relations
Intangible assets subject to amortization:
Gross Carrying Amount		$ 71.1	71.1
Accumulated Amortization		69.0	67.1
Net Carrying Amount		$ 2.1	4.0
Contractor Relations | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		2 years
Contractor Relations | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		5 years
Backlog
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years 9 months
Intangible assets subject to amortization:
Gross Carrying Amount		$ 25.0	23.1
Accumulated Amortization		19.2	17.7
Net Carrying Amount		$ 5.8	5.4
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		2 years 9 months
Noncompete Agreements
Intangible assets subject to amortization:
Gross Carrying Amount		$ 23.6	22.1
Accumulated Amortization		10.9	9.9
Net Carrying Amount		$ 12.7	12.2
Noncompete Agreements | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	4 years	2 years
Noncompete Agreements | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years	7 years
In-use software
Intangible assets subject to amortization:
Gross Carrying Amount		$ 18.9	18.9
Accumulated Amortization		16.8	16.0
Net Carrying Amount		$ 2.1	2.9
In-use software | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		6 years
Favorable Contracts
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
Intangible assets subject to amortization:
Gross Carrying Amount		$ 0.0	1.4
Accumulated Amortization		0.0	0.9
Net Carrying Amount		$ 0.0	$ 0.5
Favorable Contracts | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		5 years