CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 31.6	$ 35.1
Common stock, shares authorized (in shares)	450,000,000	450,000,000
Common stock, shares issued (in shares)	209,304,129	174,142,997