Condensed Consolidated Statements of Stockholders’ Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Balance (in shares) at Jun. 30, 2020		154.5
Balance at Jun. 30, 2020	$ 1,346.5	$ 1.6	$ 1,178.5	$ 2,302.6	$ (2,035.7)	$ (100.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	165.4			122.1		43.3
Stock option exercises	27.3		27.3
Stock-based compensation	28.5		28.5
Treasury stock acquired	(0.8)				(0.8)
Treasury stock reissued	0.0		(14.6)		14.6
Common stock dividends	(132.9)			(132.9)
Balance (in shares) at Dec. 31, 2020		154.5
Balance at Dec. 31, 2020	1,434.0	$ 1.6	1,219.6	2,291.8	(2,021.8)	(57.1)
Balance (in shares) at Sep. 30, 2020		154.5
Balance at Sep. 30, 2020	1,413.8	$ 1.6	1,198.5	2,302.1	(2,025.5)	(62.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	62.0			56.3		5.7
Stock option exercises	6.5		6.5
Stock-based compensation	18.2		18.2
Treasury stock acquired	0.0
Treasury stock reissued	0.0		(3.6)		3.6
Common stock dividends	(66.5)			(66.5)
Balance (in shares) at Dec. 31, 2020		154.5
Balance at Dec. 31, 2020	$ 1,434.0	$ 1.6	1,219.6	2,291.8	(2,021.8)	(57.1)
Balance (in shares) at Jun. 30, 2021	154.5	154.5
Balance at Jun. 30, 2021	$ 1,809.1	$ 1.6	1,245.5	2,583.8	(2,030.9)	9.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	13.3			114.4		(101.1)
Stock option exercises	40.6		40.6
Stock-based compensation	35.8		35.8
Treasury stock acquired	(1.7)				(1.7)
Treasury stock reissued	0.0		(14.2)		14.2
Common stock dividends	$ (149.1)			(149.1)
Balance (in shares) at Dec. 31, 2021	154.5	154.5
Balance at Dec. 31, 2021	$ 1,748.1	$ 1.6	1,307.7	2,549.1	(2,018.4)	(91.9)
Balance (in shares) at Sep. 30, 2021		154.5
Balance at Sep. 30, 2021	1,753.8	$ 1.6	1,263.6	2,576.6	(2,027.0)	(60.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	16.2			47.2		(31.0)
Stock option exercises	31.9		31.9
Stock-based compensation	22.5		22.5
Treasury stock acquired	(1.7)				(1.7)
Treasury stock reissued	0.0		(10.3)		10.3
Common stock dividends	$ (74.7)			(74.7)
Balance (in shares) at Dec. 31, 2021	154.5	154.5
Balance at Dec. 31, 2021	$ 1,748.1	$ 1.6	$ 1,307.7	$ 2,549.1	$ (2,018.4)	$ (91.9)