CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable, current	$ 4,356	$ 6,843
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares outstanding	65,243,000	65,137,000
Common stock, shares issued	65,243,000	65,137,000