CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable, current	$ 13,031	$ 5,382
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares outstanding	61,313,000	63,979,000
Common stock, shares issued	61,313,000	63,979,000