Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2021	Jun. 30, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts, current	$ 79.6	$ 92.5
Allowance for doubtful accounts, long-term	$ 0.3	$ 0.5
Preferred stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, shares authorized	300,000	300,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized	1,000,000,000.0	1,000,000,000.0
Common stock, shares issued	638,700,000	638,700,000
Common stock, shares outstanding	423,700,000	429,900,000
Treasury stock, shares	215,000,000.0	208,900,000
Long-term marketable securities under reverse repurchase agreements	$ 23.5	$ 13.6