Summary of Significant Accounting Policies (Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Goodwill:
Cost	$ 2,232.4	$ 2,057.2	$ 2,083.3
Impairment	472.8	472.8	472.8
Total
Total cost	3,868.7	3,598.8
Total amortization and impairment	965.1	871.1
Amortization expense	128.8	122.8	44.6
Carrying value of trade names	466.9	466.9
Software amortization expense	12.8	17.0	$ 9.8
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2018	119.5
2019	109.7
2020	98.0
2021	89.0
2022	76.1
2023 and beyond	$ 184.8
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible assets	1 year
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible assets	20 years
Software [Member]
Total
Cost	$ 166.1	174.1
Amortization and Impairment	$ 133.0	140.0
Software [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible assets	3 years
Software [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible assets	5 years
Patents and Trademarks [Member]
Total
Cost	$ 504.2	497.1
Amortization and Impairment	16.4	19.2
Other [Member]
Total
Cost	966.0	870.4
Amortization and Impairment	$ 342.9	239.1
Capitalized Software Costs [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible assets	3 years
Capitalized Software Costs [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful life of intangible assets	10 years
Customer relationships [Member] | Welch Allyn Holdings, Inc. [Member]
Total
Cost	$ 517.4	514.1
Amortization and Impairment	125.5	62.1
Customer relationships [Member] | Mortara [Member]
Total
Cost	52.3
Amortization and Impairment	4.6
Developed technology [Member] | Welch Allyn Holdings, Inc. [Member]
Total
Cost	54.0	54.0
Amortization and Impairment	16.6	$ 8.6
Developed technology [Member] | Mortara [Member]
Total
Cost	37.9
Amortization and Impairment	$ 2.9