Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019
Current Assets:
Allowance for accounts receivable	$ 1,820	$ 9,927
Common stock, $.10 par value, 160,000,000 shares authorized, 112,151,563 and 112,080,262 shares issued as of September 30, 2020 and 2019, respectively, and 107,488,242 and 108,437,904 shares outstanding as of September 30, 2020 and 2019, respectively
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	160,000,000	160,000,000
Common stock, shares issued (in shares)	112,151,563	112,080,262
Common stock, shares outstanding (in shares)	107,488,242	108,437,904
Preferred stock, no par value, 1,000,000 shares authorized, no shares issued
Preferred stock, no par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Treasury stock, at cost, 4,663,321 shares and 3,642,358 shares as of September 30, 2020 and 2019, respectively
Treasury stock (in shares)	4,663,321	3,642,358