Components of Net Deferred Income Tax Asset (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
Deferred income tax assets:
Allowance for doubtful accounts	$ 766	$ 702
Inventories	5,110	4,316
Net operating loss carry-forwards, tax credits and deferrals	6,823	2,270
Stock-based compensation	1,905	1,690
Accrued product warranty	134	809
Accrued compensated absences	467	520
Currency translation adjustments		101
Insurance and other reserves	170	105
Deferred Tax Assets, Gross, Total	15,375	10,513
Deferred income tax liabilities:
Intangible assets		31
Property, plant and equipment and other	(7,481)	(6,034)
Subtotal deferred income tax assets	7,894	4,510
Valuation allowance	(7,715)	0
Net deferred income tax assets	179	4,510
U. S.
Deferred income tax assets:
Allowance for doubtful accounts	715	681
Inventories	5,089	4,350
Net operating loss carry-forwards, tax credits and deferrals	3,000
Stock-based compensation	1,905	1,690
Accrued product warranty	130	803
Accrued compensated absences	467	520
Currency translation adjustments		101
Insurance and other reserves	170	62
Deferred Tax Assets, Gross, Total	11,476	8,207
Deferred income tax liabilities:
Intangible assets		31
Property, plant and equipment and other	(7,470)	(5,264)
Subtotal deferred income tax assets	4,006	2,974
Valuation allowance	(4,006)	0
Net deferred income tax assets		2,974
Non U. S.
Deferred income tax assets:
Allowance for doubtful accounts	51	21
Inventories	21	(34)
Net operating loss carry-forwards, tax credits and deferrals	3,823	2,270
Accrued product warranty	4	6
Insurance and other reserves		43
Deferred Tax Assets, Gross, Total	3,899	2,306
Deferred income tax liabilities:
Property, plant and equipment and other	(11)	(770)
Subtotal deferred income tax assets	3,888	1,536
Valuation allowance	(3,709)	0
Net deferred income tax assets	$ 179	$ 1,536