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Goodwill and Identifiable Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2019 | Dec. 31, 2018
Intangible Assets [Line Items] |  |  |
Write-off Intangible Asset | $ 3.3 |  |
Intangible assets subject to amortization: |  |  |
Gross Carrying Amount | 500.6 |  | $ 483.5
Accumulated Amortization | 294.6 |  | 257.0
Net Carrying Amount | 206.0 |  | 226.5
Intangible assets not subject to amortization: |  |  |
Trademarks, Carrying Amount | 258.9 | [1] | 262.2
Intangible Assets, Gross (Excluding Goodwill) | 759.5 |  | 745.7
Intangible Assets, Net (Excluding Goodwill) | 464.9 |  | 488.7
Customer and Contractual Relationships |  |  |
Intangible assets subject to amortization: |  |  |
Gross Carrying Amount | 362.1 |  | 346.9
Accumulated Amortization | 170.7 |  | 145.4
Net Carrying Amount | $ 191.4 |  | 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 | $ 71.0 |  | 71.1
Accumulated Amortization | 70.5 |  | 67.1
Net Carrying Amount | $ 0.5 |  | 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 subject to amortization: |  |  |
Gross Carrying Amount | $ 25.0 |  | 23.1
Accumulated Amortization | 22.3 |  | 17.7
Net Carrying Amount | $ 2.7 |  | 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 | 12.8 |  | 9.9
Net Carrying Amount | $ 10.8 |  | 12.2
Noncompete Agreements | Minimum [Member] |  |  |
Intangible Assets [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 2 years |  |
Noncompete Agreements | Maximum [Member] |  |  |
Intangible Assets [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 7 years |  |
In-use software |  |  |
Intangible assets subject to amortization: |  |  |
Gross Carrying Amount | $ 18.9 |  | 18.9
Accumulated Amortization | 18.3 |  | 16.0
Net Carrying Amount | $ 0.6 |  | 2.9
In-use software | Minimum [Member] |  |  |
Intangible Assets [Line Items] |  |  |
Finite-Lived Intangible Asset, Useful Life | 6 years |  |
Favorable Contracts |  |  |
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 |  |
[1] | Certain foreign trademarks totaling $3.3 million were written off during the second quarter of 2019.

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