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Nature of Operations and Summary of Significant Accounting Policies - Schedule of Changes in Allowance for Slow Moving and Obsolete Inventories (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Inventory Disclosure [Abstract]
Balance, beginning of year	$ 3,826,000	$ 3,869,000
Charged to cost of sales	262,000	77,000
Disposal of inventory, net of recoveries	(315,000)	(120,000)
Balance, end of year	$ 3,773,000	$ 3,826,000

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- Definition

Inventory reserve charged to costs of sales.

+ References

No definition available.

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- Definition

Amount by which inventory stated at last-in first-out (LIFO) is less than (in excess of) inventory stated at other inventory cost methods.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(c))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount of loss from reductions in inventory due to subsequent measurement adjustments, including, but not limited to, physical deterioration, obsolescence, or changes in price levels.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section 35
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=68049868&loc=SL66093879-108312

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-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
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-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

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-Name Accounting Standards Codification
-Topic 330
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