CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Millions	Total	Common Stock, Par Value of $5	Common Stock, Capital in Excess of Par Value	Reinvested Earnings	Common Stock in Treasury	Accumulated Other Comprehensive (Loss) Income
Balances at the beginning of the period at Jun. 30, 2019	$ 1,520.1	$ 279.0	$ 320.4	$ 1,605.3	$ (332.8)	$ (351.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	80.0			80.0
Pension and postretirement benefits gain, net of tax	6.0					6.0
Net (loss) gain on derivative instruments, net of tax	7.6					7.6
Foreign currency translation gain	1.9					1.9
Cash Dividends:
Common	(19.4)			(19.4)
Share-based compensation plans	3.0	0.5	(1.9)		4.4
Stock options exercised	4.2	0.6	3.6
Balances at the end of the period at Dec. 31, 2019	1,603.4	280.1	322.1	1,665.9	(328.4)	(336.3)
Balances at the beginning of the period at Sep. 30, 2019	1,577.0	279.8	317.5	1,636.8	(329.5)	(327.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	38.8			38.8
Pension and postretirement benefits gain, net of tax	3.0					3.0
Net (loss) gain on derivative instruments, net of tax	(19.1)					(19.1)
Foreign currency translation gain	7.4					7.4
Cash Dividends:
Common	(9.7)			(9.7)
Share-based compensation plans	4.3		3.2		1.1
Stock options exercised	1.7	0.3	1.4
Balances at the end of the period at Dec. 31, 2019	1,603.4	280.1	322.1	1,665.9	(328.4)	(336.3)
Balances at the beginning of the period at Jun. 30, 2020	1,445.7	280.1	321.4	1,568.0	(325.8)	(398.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(132.0)			(132.0)
Pension and postretirement benefits gain, net of tax	7.2					7.2
Net (loss) gain on derivative instruments, net of tax	13.2					13.2
Foreign currency translation gain	14.5					14.5
Cash Dividends:
Common	(19.5)			(19.5)
Share-based compensation plans	3.8		(4.4)		8.2
Balances at the end of the period at Dec. 31, 2020	1,332.9	280.1	317.0	1,416.5	(317.6)	(363.1)
Balances at the beginning of the period at Sep. 30, 2020	1,407.5	280.1	315.9	1,511.2	(319.3)	(380.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(84.9)			(84.9)
Pension and postretirement benefits gain, net of tax	3.6					3.6
Net (loss) gain on derivative instruments, net of tax	4.9					4.9
Foreign currency translation gain	8.8					8.8
Cash Dividends:
Common	(9.8)			(9.8)
Share-based compensation plans	2.8		1.1		1.7
Balances at the end of the period at Dec. 31, 2020	$ 1,332.9	$ 280.1	$ 317.0	$ 1,416.5	$ (317.6)	$ (363.1)