Revenue Recognition - Dual Reporting - Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2019	Oct. 01, 2018	Sep. 30, 2018
Current assets:
Receivables	$ 1,222.6	$ 1,194.6	$ 1,190.1
Other current assets	153.5	167.0	149.3
Deferred income taxes	198.1	180.8	179.6
Other assets	118.3	107.6	96.2
Current liabilities:
Contract liabilities	293.7	268.6	249.9
Customer returns, rebates and incentives	192.6	211.0	206.6
Other current liabilities	322.8	232.2	226.6
Shareowners’ equity:
Retained earnings	6,431.6	6,204.2	6,198.1
Accumulated other comprehensive loss	(930.2)		(941.9)
Impact of Adoption | Accounting Standards Update 2014-09
Current assets:
Receivables	(3.1)	4.5
Other current assets	(15.9)	17.7
Deferred income taxes	(1.1)	1.2
Other assets	(10.3)	11.4
Current liabilities:
Contract liabilities	(17.3)	18.7
Customer returns, rebates and incentives	(2.3)	4.4
Other current liabilities	(4.4)	5.6
Shareowners’ equity:
Retained earnings	(6.6)	$ 6.1
Accumulated other comprehensive loss	0.2
Balances without adoption of ASC 606
Current assets:
Receivables	1,219.5		1,190.1
Other current assets	137.6		149.3
Deferred income taxes	197.0		179.6
Other assets	108.0		96.2
Current liabilities:
Contract liabilities	276.4		249.9
Customer returns, rebates and incentives	190.3		206.6
Other current liabilities	318.4		226.6
Shareowners’ equity:
Retained earnings	6,425.0		$ 6,198.1
Accumulated other comprehensive loss	$ (930.0)