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Nature of Operations and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Exercisable stock options, included in the diluted earnings per share calculation |  |  | 337,000 | 84,000
Common Stock Equivalents |  |  | 72,000 | 2,000
Anit-dilutive exercisable stock options, not included in the diluted earnings per share calculation |  |  | 8,000 | 261,000
Net unrealized gains |  |  | $ 167,000 | $ 1,141,000
Transfers of investments between Level 1 and Level 2 | 0 | 0 | 0 | 0
Estimated interest accrued |  | 399,000 |  | 399,000
Impairment loss recognized on an asset group |  |  | 0 | 0
Time for the collection of cost associated with Pre- contract |  |  | 1 year |
Valuation allowance | 0 | 0 | 0 | 0
Separate U.S. Corporate Entities Affiliated With A Foreign-Based Global Company [Member] | Revenue [Member] |  |  |  |
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Percentage of concentration | 5.00% | 4.00% | 16.00% | 11.00%
Three to Four Years Old Inventory [Member] |  |  |  |
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Cost basis reduction in inventory, percentage | 50.00% |  | 50.00% |
Three to Four Years Old Inventory [Member] | Minimum [Member] |  |  |  |
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Inventory, time period on the shelf, years |  |  | 3 years |
Three to Four Years Old Inventory [Member] | Maximum [Member] |  |  |  |
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Inventory, time period on the shelf, years |  |  | 4 years |
Four to Five Years Old Inventory [Member] |  |  |  |
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Cost basis reduction in inventory, percentage | 75.00% |  | 75.00% |
Four to Five Years Old Inventory [Member] | Minimum [Member] |  |  |  |
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Inventory, time period on the shelf, years |  |  | 4 years |
Four to Five Years Old Inventory [Member] | Maximum [Member] |  |  |  |
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Inventory, time period on the shelf, years |  |  | 5 years |
Greater Than Five Years Old Inventory [Member] |  |  |  |
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Inventory valuation estimate | $ 0 |  | $ 0 |
Greater Than Five Years Old Inventory [Member] | Minimum [Member] |  |  |  |
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Inventory, time period on the shelf, years |  |  | 5 years |

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