Condensed Consolidated Balance Sheets - USD ($)	Dec. 31, 2016	Sep. 30, 2016
Current assets:
Cash and cash equivalents	$ 20,562,000	$ 18,219,000
Marketable securities at fair value (cost $86,498,000 at December 31, 2016 and $86,203,000 at September 30, 2016)	86,386,000	85,938,000
Accounts receivable, less allowance for doubtful accounts of $192,000 at December 31, 2016 and $195,000 at September 30, 2016	794,000	1,110,000
Costs and estimated earnings in excess of billings	6,691,000	4,921,000
Inventories, net	12,537,000	11,634,000
Prepaid expenses & other current assets	1,536,000	1,598,000
Total Current Assets	128,506,000	123,420,000
Property and equipment, net of accumulated depreciation	5,181,000	5,239,000
Other assets	53,000	53,000
Total Assets	133,740,000	128,712,000
Current Liabilities:
Accounts payable	1,891,000	1,443,000
Customer deposits	7,517,000	4,484,000
Accrued expenses	2,343,000	2,264,000
Total Current Liabilities	11,751,000	8,191,000
Deferred and other income taxes	362,000	316,000
Total Liabilities	12,113,000	8,507,000
Commitments and contingencies
Shareholders' equity:
Preferred stock, par value $.10 per share; authorized 300,000 shares; none issued
Capital in excess of par value	10,915,000	10,887,000
Retained earnings	109,275,000	107,881,000
Total Shareholders' Equity	121,627,000	120,205,000
Total Liabilities and Shareholders' Equity	133,740,000	128,712,000
Common Stock [Member]
Shareholders' equity:
Common stock	1,211,000	1,211,000
Class B Stock [Member]
Shareholders' equity:
Common stock	$ 226,000	$ 226,000