CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) Statement - USD ($) shares in Millions, $ in Millions	Total	Common Stock, Value [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Other Comprehensive Income (Loss) [Member]
Stockholders' Equity	$ 2,750.9	$ 2.4	$ (45.6)	$ 1,431.9	$ 1,376.5	$ (14.3)
Common Stock, Shares		239.8
Treasury Stock, Shares			(3.1)
Stockholders' Equity	2,770.0	$ 2.4	$ (54.8)	1,451.9	1,384.8	(14.3)
Net income (loss)	13.1				13.1
Cash dividends paid, $0.02 per share	(4.8)				(4.8)
Share-based compensation, Shares		2.3
Share-based compensation	10.8	$ 0.0	$ (9.2)	20.0
Shares Paid for Tax Withholding for Share Based Compensation			(1.2)
Change in pension and postretirement liability, net of tax	0.0					0.0
Stockholders' Equity at Sep. 30, 2019	2,770.0	2.4	$ (54.8)	1,451.9	1,384.8	(14.3)
Stockholders' Equity	2,689.3	$ 2.4	$ (53.6)	1,446.3	1,308.6	(14.4)
Common Stock, Shares		242.0
Treasury Stock, Shares			(4.1)
Stockholders' Equity	2,770.0	$ 2.4	$ (54.8)	1,451.9	1,384.8	(14.3)
Net income (loss)	81.0				81.0
Cash dividends paid, $0.02 per share	(4.8)				(4.8)
Share-based compensation, Shares		0.1
Share-based compensation	4.4		$ (1.2)	5.6
Shares Paid for Tax Withholding for Share Based Compensation			(0.2)
Change in pension and postretirement liability, net of tax	0.1					0.1
Stockholders' Equity at Sep. 30, 2019	2,770.0	$ 2.4	$ (54.8)	1,451.9	1,384.8	(14.3)
Stockholders' Equity	2,770.0	$ 2.4	$ (54.8)	1,451.9	1,384.8	(14.3)
Common Stock, Shares		242.1
Treasury Stock, Shares			(4.3)
Stockholders' Equity	$ 2,660.6	$ 2.4	$ (55.4)	1,456.5	1,269.6	(12.5)
Common Stock, Shares		242.1
Treasury Stock, Shares	(4.4)		(4.4)
Stockholders' Equity	$ 2,798.6	$ 2.5	$ (56.7)	1,466.2	1,398.6	(12.0)
Net income (loss)	133.8				133.8
Cash dividends paid, $0.02 per share	(4.8)				(4.8)
Share-based compensation, Shares		5.1
Share-based compensation	8.5	$ 0.1	$ (1.3)	9.7	0.0	0.0
Shares Paid for Tax Withholding for Share Based Compensation			(0.6)
Change in pension and postretirement liability, net of tax	0.5					0.5
Stockholders' Equity at Sep. 30, 2020	2,798.6	2.5	$ (56.7)	1,466.2	1,398.6	(12.0)
Stockholders' Equity	2,844.9	$ 2.5	$ (56.6)	1,463.3	1,447.8	(12.1)
Common Stock, Shares		247.2
Treasury Stock, Shares			(4.9)
Stockholders' Equity	2,798.6	$ 2.5	$ (56.7)	1,466.2	1,398.6	(12.0)
Net income (loss)	(49.2)				(49.2)
Share-based compensation, Shares		0.0
Share-based compensation	2.8		$ (0.1)	2.9
Shares Paid for Tax Withholding for Share Based Compensation			(0.1)
Change in pension and postretirement liability, net of tax	0.1					0.1
Stockholders' Equity at Sep. 30, 2020	2,798.6	$ 2.5	$ (56.7)	1,466.2	1,398.6	(12.0)
Stockholders' Equity	$ 2,798.6	$ 2.5	$ (56.7)	$ 1,466.2	$ 1,398.6	$ (12.0)
Common Stock, Shares		247.2
Treasury Stock, Shares	(5.0)		(5.0)