Income Taxes - Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Effective income tax rate reconciliation
Statutory federal tax rate (as a percent)	35.00%	35.00%	35.00%
Tax provision for income taxes at the statutory rate	$ 1,313	$ 16,512	$ 1,792
Foreign tax rate differentials	(1,505)	(1,417)	(605)
Provision for state taxes, net of federal taxes	778	818	230
U.S. tax on distributed and undistributed earnings of foreign subsidiaries	523	419	173
Manufacturer's deduction	(98)	(1,213)
Tax credits	(1,198)	(240)	(91)
State tax rate reduction impact on deferred tax asset	(1,819)	1,565	157
Change in Valuation Allowance	408	128
Other, net	329	118	(287)
Total provision for income taxes	$ (1,269)	$ 16,690	$ 1,369
Effective tax rate (as a percent)	(33.80%)	35.40%	26.70%