CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Net sales	$ 5,382.1	$ 4,437.8	$ 10,334.3	$ 8,839.3
Cost of goods sold	4,378.4	3,688.2	8,534.0	7,336.8
Gross profit	1,003.7	749.6	1,800.3	1,502.5
Selling, general and administrative, excluding intangible amortization	493.1	458.4	946.0	876.2
Selling, general and administrative intangible amortization	88.1	88.6	176.1	180.5
Loss (gain) on disposal of assets	2.5	0.3	(11.4)	2.8
Multiemployer pension withdrawal income			(3.3)
Restructuring and other costs	363.4	5.2	365.7	12.9
Operating profit	56.6	197.1	327.2	430.1
Interest expense, net	(72.5)	(83.5)	(159.2)	(177.3)
Loss on extinguishment of debt	(8.2)		(8.2)	(1.1)
Pension and other postretirement non-service income	39.7	35.0	79.6	69.9
Other income (expense), net	6.3	(13.4)	6.5	7.4
Equity in income of unconsolidated entities	20.6	9.7	39.0	18.7
Income before income taxes	42.5	144.9	284.9	347.7
Income tax expense	(1.8)	(30.5)	(60.4)	(80.8)
Consolidated net income	40.7	114.4	224.5	266.9
Less: Net income attributable to noncontrolling interests	(0.8)	(1.9)	(2.3)	(2.4)
Net income attributable to common stockholders	$ 39.9	$ 112.5	$ 222.2	$ 264.5
Basic earnings per share attributable to common stockholders	$ 0.15	$ 0.42	$ 0.84	$ 1.00
Diluted earnings per share attributable to common stockholders	$ 0.15	$ 0.42	$ 0.83	$ 0.99
Basic weighted average shares outstanding	263.4	264.9	264.0	263.8
Diluted weighted average shares outstanding	265.3	267.0	266.1	265.9