Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2017	Jun. 30, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts - trade receivables - Current	$ 54.0	$ 49.6
Allowance for doubtful accounts - trade receivables - Long-term	$ 0.8	$ 0.8
Preferred stock, par value (in US$ per share)	$ 1.00	$ 1.00
Preferred stock, shares authorized (in shares)	300,000.0	300,000.0
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in US$ per share)	$ 0.1	$ 0.10
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	638,700,000	638,700,000
Common stock, shares outstanding (in shares)	444,000,000	445,000,000
Treasury stock, (in shares)	194,700,000	193,700,000
Short-term Marketable Securities Under Reverse Repurchase Agreements	$ 110.0	$ 0.0
Long-term Marketable Securities Under Reverse Repurchase Agreements	19.3	0.0
Cash And Cash Equivalents Under Reverse Repurchase Agreements	$ 0.1	$ 0.0