Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Sep. 30, 2019
Current assets:
Restricted cash	$ 2,880	$ 1,500
Allowance, accounts receivable	$ 4,053	$ 7,908
Stockholders' equity:
Preferred stock, par value	$ 0.003	$ 0.003
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.001455	$ 0.001455
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	72,960,000	72,960,000
Treasury stock, shares	10,677,000	11,040,000
Treasury stock held for deferred compensation, shares	216,000	211,000