Consolidated Balance Sheets - USD ($)		Sep. 30, 2017	Sep. 30, 2016
Current assets:
Cash and cash equivalents		$ 22,933,000	$ 18,219,000
Marketable securities at fair value (cost of $86,967,000 at September 30, 2017 and $86,203,000 at September 30, 2016)		87,886,000	85,938,000
Accounts receivable, less allowance for doubtful accounts of $207,000 at September 30, 2017 and $195,000 at September 30, 2016		1,184,000	1,110,000
Costs and estimated earnings in excess of billings		6,768,000	4,921,000
Inventories, net		16,687,000	11,634,000
Prepaid expenses		1,660,000	1,598,000
Total current assets		137,118,000	123,420,000
Property and equipment, net		5,722,000	5,239,000
Other assets		53,000	53,000
Total Assets		142,893,000	128,712,000
Current liabilities:
Accounts payable		1,320,000	1,443,000
Customer deposits		8,628,000	4,484,000
Accrued expenses		2,426,000	2,264,000
Total current liabilities		12,374,000	8,191,000
Deferred and other income taxes		1,601,000	316,000
Total liabilities		13,975,000	8,507,000
Commitments and contingencies
Shareholders' equity:
Preferred stock, par value $.10 per share; 300,000 shares authorized; none issued
Capital in excess of par value		11,178,000	10,887,000
Retained earnings		116,299,000	107,881,000
Total shareholders' equity		128,918,000	120,205,000
Total Liabilities and Shareholders' Equity		142,893,000	128,712,000
Common Stock [Member]
Shareholders' equity:
Common stock	[1]	1,215,000	1,211,000
Total shareholders' equity	[2]	1,215,000	1,211,000
Class B Stock [Member]
Shareholders' equity:
Common stock	[1]	226,000	226,000
Total shareholders' equity	[2]	$ 226,000	$ 226,000

[1] 2016 adjusted for three-for-two stock split

[2] 2016 and 2015 adjusted for three-for-two stock split