Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 1,551,000	$ 2,489,000
Adjustments to reconcile net income to cash provided by operating activities:
Purchase of marketable securities	(33,191,000)	(35,313,000)
Proceeds from sale and maturity of marketable securities	32,680,000	34,659,000
Change in value of marketable securities	(2,040,000)	(1,256,000)
Deferred and other income taxes	382,000	(1,657,000)
Depreciation and amortization	586,000	418,000
Stock-based compensation		18,000
Changes in assets and liabilities:
Accounts receivable	(772,000)	(59,000)
Costs and estimated earnings in excess of billings	1,696,000	455,000
Inventories (excluding the effect of the Blaw-Knox acquisition)	2,617,000	(325,000)
Prepaid expenses	75,000	(955,000)
Accounts payable	1,496,000	807,000
Customer deposits	(1,156,000)	3,003,000
Accrued expenses	(219,000)	1,763,000
Total adjustments	2,154,000	1,558,000
Cash flows provided by operating activities	3,705,000	4,047,000
Cash flows from investing activities:
Acquisition of Blaw-Knox	(14,400,000)
Capital expenditures	(932,000)	(6,000)
Cash flows used in investing activities	(15,332,000)	(6,000)
Net increase (decrease) in cash and cash equivalents	(11,627,000)	4,041,000
Cash and cash equivalents at:
Beginning of year	35,584,000	10,302,000
End of year	23,957,000	$ 14,343,000
Non-cash investing and financing activities:
Operating lease right-of-use assets	254,000
Operating lease liabilities	$ 254,000