CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance for doubtful accounts	$ 0.9	$ 0.9
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	3,000,000	3,000,000
Common stock, shares outstanding (in shares)	551,369	537,715