Revenue Recognition - Summary of Effect of Adoption of ASC 606 Impact on Condensed Consolidated Statements of Income (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
	Oct. 01, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Net sales		$ 4,690.0	$ 4,137.5	$ 13,637.4	$ 12,048.5
Cost of goods sold		3,701.1	3,270.4	10,967.1	9,618.5
Income tax (expense) benefit		(77.6)	(84.5)	(187.5)	969.9
Consolidated net income		253.8	$ 271.3	555.5	$ 1,629.3
ASC 606 [Member] | Balances Without Adoption of ASC 606 [Member]
Disaggregation Of Revenue [Line Items]
Net sales		4,690.1		13,640.2
Cost of goods sold		3,702.1		10,972.2
Income tax (expense) benefit		(77.3)		(186.9)
Consolidated net income		253.2		553.8
ASC 606 [Member] | Impact of Adoption Increase/(Decrease) [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ 183.7	(0.1)		(2.8)
Cost of goods sold	133.4	(1.0)		(5.1)
Income tax (expense) benefit	$ (6.8)	(0.3)		(0.6)
Consolidated net income		$ 0.6		$ 1.7