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Identifiable Intangible Assets Schedule of Intangible Assets and Goodwill (Details) - USD ($) $ in Millions | Sep. 30, 2018 | Sep. 30, 2017 | Feb. 15, 2017
--- | --- | --- | ---
Indefinite-lived intangible assets: |  |  |
Goodwill | $ 12.1 | $ 12.9 | $ 7.2
Intangible Assets, Gross (Excluding Goodwill) | 720.1 | 715.6 |
Accumulated amortization: |  |  |
Accumulated Amortization | 313.3 | 293.4 |
Intangible Assets, Net (Including Goodwill) | 420.2 | 439.3 |
Business Combination-Related Identifiable Intangible [Member] |  |  |
Accumulated amortization: |  |  |
Net book value | 406.8 | 422.2 |
Trademarks and Trade Names [Member] |  |  |
Indefinite-lived intangible assets: |  |  |
Trade names and trademarks | 266.6 | 266.8 |
Software and Software Development Costs [Member] |  |  |
Capitalized external-use software: |  |  |
Capitalized Computer Software, Gross | 27.6 | 28.4 |
Accumulated amortization | 14.2 | 11.3 |
Net book value | 13.4 | 17.1 |
Technology-Based Intangible Assets [Member] |  |  |
Finite-lived intangible assets: |  |  |
Technology | 82.6 | 76.7 |
Accumulated amortization: |  |  |
Accumulated Amortization | 72.9 | 72.2 |
Customer Relationships [Member] |  |  |
Finite-lived intangible assets: |  |  |
Customer relationships and other | 358.8 | 359.2 |
Accumulated amortization: |  |  |
Accumulated Amortization | $ 240.4 | $ 221.2 |

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