Goodwill and Purchased Intangible Assets (Details 3) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Purchased intangible assets
Weighted-Average Life (in years)	14 years 6 months	14 years 6 months
Gross	$ 783.8	$ 783.4
Accumulated Amortization	(618.0)	(564.5)
Net	165.8	218.9
Non-amortizable trade names	387.7	387.8
Intangible assets excluding goodwill, gross	1,171.5	1,171.2
Purchased intangible assets, net	553.5	$ 606.7
Future amortization expense of purchased intangible assets for the five years succeeding fiscal years
2017	45.8
2018	38.3
2019	36.9
2020	11.0
2021	$ 5.3
Distribution network
Purchased intangible assets
Weighted-Average Life (in years)	39 years 1 month	39 years 1 month
Gross	$ 55.4	$ 55.4
Accumulated Amortization	(28.0)	(26.6)
Net	$ 27.4	$ 28.8
Distribution network | Pierce
Purchased intangible assets
Weighted-Average Life (in years)	40 years
Net	$ 26.5
Non-compete
Purchased intangible assets
Weighted-Average Life (in years)	10 years 6 months	10 years 6 months
Gross	$ 56.4	$ 56.4
Accumulated Amortization	(56.4)	(56.3)
Net	$ 0.0	$ 0.1
Technology-related
Purchased intangible assets
Weighted-Average Life (in years)	11 years 11 months	11 years 11 months
Gross	$ 104.7	$ 104.8
Accumulated Amortization	(91.5)	(83.3)
Net	$ 13.2	$ 21.5
Customer relationships
Purchased intangible assets
Weighted-Average Life (in years)	12 years 9 months	12 years 9 months
Gross	$ 550.8	$ 550.3
Accumulated Amortization	(427.4)	(384.0)
Net	$ 123.4	$ 166.3
Other
Purchased intangible assets
Weighted-Average Life (in years)	16 years 4 months	16 years 6 months
Gross	$ 16.5	$ 16.5
Accumulated Amortization	(14.7)	(14.3)
Net	$ 1.8	$ 2.2