Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Net income (loss)	$ 461	$ 10,144	$ (2,407)	$ 4,730
Weighted average shares - basic	27,103	26,973	27,095	26,968
Effect of dilutive securities (in shares)	56	22		18
Weighted average shares - diluted	27,159	26,995	27,095	26,986
Net income (loss) per share, basic (in dollars per share)	$ 0.02	$ 0.38	$ (0.09)	$ 0.18
Net income (loss) per share, diluted (in dollars per share)	$ 0.02	$ 0.38	$ (0.09)	$ 0.18
RSUs
Anti-dilutive employee share-based awards	0	0	1,000	0