Condensed Consolidated Balance Sheets - USD ($)	Jun. 30, 2016	Sep. 30, 2015
Current Assets:
Cash and cash equivalents	$ 10,888,000	$ 11,152,000
Marketable securities at fair value (cost $86,090,000 at June 30, 2016 and $87,123,000 at September 30, 2015)	85,612,000	84,357,000
Accounts receivable, less allowance for doubtful accounts of $203,000 at June 30, 2016 and $357,000 at September 30, 2015	1,499,000	874,000
Costs and estimated earnings in excess of billings	9,737,000	2,396,000
Inventories, net	11,557,000	12,770,000
Prepaid expenses and other current assets	511,000	817,000
Total Current Assets	119,804,000	112,366,000
Property and equipment, net	5,502,000	6,388,000
Deferred and other income taxes	535,000	1,331,000
Other assets	53,000	59,000
Total Assets	125,894,000	120,144,000
Current Liabilities:
Accounts payable	1,193,000	1,529,000
Customer deposits	3,608,000	4,418,000
Accrued expenses and other current liabilities	2,840,000	1,452,000
Total Current Liabilities	7,641,000	7,399,000
Commitments and contingencies
Shareholders' equity:
Preferred stock, par value $.10 per share; authorized 300,000 shares; none issued
Capital in excess of par value	11,140,000	10,953,000
Retained earnings	106,157,000	100,838,000
Total Shareholders' Equity	118,253,000	112,745,000
Total Liabilities and Shareholders' Equity	125,894,000	120,144,000
Common Stock [Member]
Shareholders' equity:
Common stock	805,000	803,000
Class B Stock [Member]
Shareholders' equity:
Common stock	$ 151,000	$ 151,000