Condensed Consolidated Balance Sheets (USD $)	Jun. 30, 2013	Sep. 30, 2012
Current Assets:
Cash	$ 8,491,000	$ 3,361,000
Marketable securities at fair value (cost $80,741,000 at June 30, 2013 and $80,568,000 at September 30, 2012)	82,023,000	81,375,000
Accounts receivable, less allowance for doubtful accounts of $234,000 at June 30, 2013 and $368,000 at September 30, 2012	1,142,000	1,206,000
Costs and estimated earnings in excess of billings	2,665,000	3,448,000
Inventories, net	11,894,000	11,918,000
Prepaid expenses and other current assets	2,257,000	782,000
Total Current Assets	108,472,000	102,090,000
Property and equipment, net	8,354,000	8,127,000
Other assets	87,000	95,000
Total Assets	116,913,000	110,312,000
Current Liabilities:
Accounts payable	1,695,000	1,881,000
Customer deposits	1,569,000	480,000
Accrued expenses and other current liabilities	2,846,000	3,517,000
Total Current Liabilities	6,110,000	5,878,000
Deferred and other income taxes	2,668,000	974,000
Total Liabilities	8,778,000	6,852,000
Commitments and contingencies
Shareholders' equity:
Preferred stock, par value $.10 per share; authorized 300,000 shares; none issued
Common stock	801,000	801,000
Capital in excess of par value	10,233,000	10,049,000
Retained earnings	96,950,000	92,459,000
Total Shareholders' Equity	108,135,000	103,460,000
Total Liabilities and Shareholders' Equity	116,913,000	110,312,000
Class B Stock [Member]
Shareholders' equity:
Common stock	$ 151,000	$ 151,000