Changes in Product Warranty Reserve (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Changes in product warranty reserve
Balance at the beginning of the year	$ 951	$ 1,952	$ 2,308
Accruals for warranties issued during the year	4,984	324	681
Settlements made (in cash or in kind) during the year	(3,609)	(1,325)	(1,037)
Balance at the end of the year	$ 2,326	$ 951	$ 1,952