Condensed Consolidated Balance Sheets - USD ($)	Jun. 30, 2019	Sep. 30, 2018
Current assets:
Cash and cash equivalents	$ 6,435,000	$ 8,012,000
Marketable securities at fair value (cost $104,556,000 at June 30, 2019 and $103,751,000 at September 30, 2018)	104,767,000	104,058,000
Accounts receivable, less allowance for doubtful accounts of $341,000 at June 30, 2019 and $313,000 at September 30, 2018	1,482,000	993,000
Costs and estimated earnings in excess of billings	20,522,000	11,900,000
Inventories, net	19,995,000	18,214,000
Prepaid expenses and other current assets	945,000	1,904,000
Total current assets	154,146,000	145,081,000
Property and equipment, net	8,301,000	7,889,000
Other assets	53,000	53,000
Total Assets	162,500,000	153,023,000
Current liabilities:
Accounts payable	2,594,000	1,838,000
Customer deposits	2,462,000	4,563,000
Accrued expenses and other current liabilities	2,662,000	2,085,000
Total current liabilities	7,718,000	8,486,000
Deferred and other income taxes	2,333,000	2,358,000
Total liabilities	10,051,000	10,844,000
Commitments and contingencies
Shareholders' equity:
Preferred stock, par value $.10 per share; 300,000 shares authorized; none issued
Capital in excess of par value	11,915,000	11,862,000
Retained earnings	139,080,000	128,863,000
Total shareholders' equity	152,449,000	142,179,000
Total Liabilities and Shareholders' Equity	162,500,000	153,023,000
Common Stock [Member]
Shareholders' equity:
Common stock	1,225,000	1,225,000
Total shareholders' equity	1,225,000	1,225,000
Class B Stock [Member]
Shareholders' equity:
Common stock	229,000	229,000
Total shareholders' equity	$ 229,000	$ 229,000