Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operations:
Net income	$ 4,490,000	$ 4,833,000
Adjustments to reconcile net income to cash provided by operating activities:
Purchases of marketable securities	(52,657,000)	(41,816,000)
Proceeds from sale and maturity of marketable securities	52,762,000	41,519,000
Change in fair value of marketable securities	(753,000)	(3,455,000)
Deferred income taxes	1,694,000	1,365,000
Depreciation and amortization	881,000	798,000
Provision for doubtful accounts	40,000	366,000
Stock-based compensation	184,000	138,000
Change in assets and liabilities:
Accounts receivable	24,000	(190,000)
Costs and estimated earnings in excess of billings	783,000	234,000
Inventories	24,000	895,000
Prepaid expenses and other current assets	(1,475,000)	268,000
Accounts payable	(186,000)	1,393,000
Customer deposits	1,089,000	1,762,000
Accrued expenses and other	(663,000)	1,708,000
Total adjustments	1,747,000	4,985,000
Cash flows provided by operating activities	6,237,000	9,818,000
Cash flows used in investing activities:
Capital expenditures	(1,107,000)	(773,000)
Cash flows used in investing activities	(1,107,000)	(773,000)
Net increase in cash	5,130,000	9,045,000
Cash at:
Beginning of period	3,361,000	1,715,000
End of period	$ 8,491,000	$ 10,760,000