Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	6 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Cash flows from operations:
Net Income	$ 89,000us-gaap_NetIncomeLoss	$ 2,347,000us-gaap_NetIncomeLoss
Adjustments to reconcile net income to cash provided by (used in) operating activities:
Purchases of marketable securities	(213,920,000)	(67,849,000)
Proceeds from sale and maturity of marketable securities	213,392,000	66,005,000
Change in fair value of marketable securities	240,000	(809,000)
Deferred income taxes	(303,000)	574,000
Depreciation and amortization	668,000	676,000
Provision for doubtful accounts	10,000us-gaap_ProvisionForDoubtfulAccounts	15,000us-gaap_ProvisionForDoubtfulAccounts
Stock-based compensation	127,000us-gaap_ShareBasedCompensation	136,000us-gaap_ShareBasedCompensation
Changes in assets and liabilities:
Accounts receivable	(658,000)	(4,000)
Costs and estimated earnings in excess of billings	(2,000,000)	(5,473,000)
Inventories	387,000us-gaap_IncreaseDecreaseInInventories	1,379,000us-gaap_IncreaseDecreaseInInventories
Prepaid expenses and other current assets	(47,000)	396,000
Accounts payable	987,000	241,000
Customer deposits	4,335,000	(2,000)
Accrued expenses and other	(229,000)	(940,000)
Total adjustments	2,989,000	(5,655,000)
Cash flows provided by (used in) operating activities	3,078,000	(3,308,000)
Cash flows used in investing activities:
Capital expenditures	(261,000)	(597,000)
Cash flows used in investing activities	(261,000)	(597,000)
Net increase (decrease) in cash	2,817,000	(3,905,000)
Cash and cash equivalents at:
Beginning of period	7,193,000	9,557,000
End of period	$ 10,010,000	$ 5,652,000

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