CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Accounts receivable, allowances for doubtful accounts	$ 11,724	$ 14,333
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	560,000,000	560,000,000
Common stock, shares issued	291,504,000	293,938,000
Common stock, shares outstanding	285,753,000	290,187,000
Treasury stock, shares	3,751,000	3,751,000