Supplemental Balance Sheet Disclosures - Unbilled Receivables (Details) - USD ($)	3 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2016
Unbilled receivables
Unbilled receivables, net of progress payments	$ 1,604,069		$ 1,597,672
Change in operating income resulting from revised estimates	(1,595,295)	$ (308,733)
Inventories
Raw materials	3,173,982		2,966,891
Work-in-process	688,537		500,869
Finished goods	335,913		178,068
Inventory, Net, Total	4,198,432		3,645,828
Prepaid expenses and other current assets
Prepaid insurance	498,139		386,212
Income tax refund receivable	479,726		106,932
Other	244,730		354,063
Total	1,222,595		847,207
Delta
Unbilled receivables
Provision for loss on unbilled receivables	3,600,000		3,600,000
Unbilled receivables, net of progress payments	1,600,000		$ 1,600,000
Contracts accounted for under percentage of completion
Unbilled receivables
Change in operating income resulting from revised estimates	$ 154,000	$ (46,000)

Amount of provision related to unbilled receivables not expected to be collected.

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