CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets
Cash	$ 14,995	$ 8,764
Investment securities, available-for-sale, at fair value	1,243	1,228
Accounts receivable, net
Trade - billed (less allowance for doubtful accounts of approximately $400), including contract retentions	12,572	9,798
Trade - unbilled	483	742
Inventories, net
Raw materials	1,697	643
Finished goods	1,499	1,551
Prepaid expenses and other assets	622	615
Total current assets	33,111	23,341
Property and equipment, net	18,249	18,602
Deferred buy-back lease asset, net	3,608	4,237
Other assets	278	319
Total assets	55,246	46,499
Current liabilities
Accounts payable - trade	3,166	1,866
Accrued expenses and other liabilities	789	875
Deferred revenue	3,056	1,774
Accrued compensation	1,250	1,318
Accrued income taxes	1,486	470
Deferred buy-back lease obligation	1,090	1,203
Operating lease liabilities	88	85
Current maturities of notes payable	486	740
Customer deposits	1,623	569
Total current liabilities	13,034	8,900
Deferred revenue	1,277	600
Deferred buy-back lease obligation	3,000	3,790
Operating lease liabilities	144	211
Notes payable - less current maturities	3,879	4,196
PPP loan	0	2,692
Deferred tax liability	2,458	2,461
Total liabilities	23,792	22,850
Stockholders' equity
Preferred stock, $.01 par value; authorized 1,000,000 shares, none issued and outstanding	0	0
Common stock, $.01 par value; authorized 8,000,000 shares; 5,326,595 and 5,279,411 issued and 5,202,158 and 5,202,158 outstanding, respectively	53	52
Additional paid-in capital	6,663	6,405
Treasury stock, at cost, 40,920 shares	(102)	(102)
Retained earnings	24,840	17,294
Total stockholders' equity	31,454	23,649
Total liabilities and stockholders' equity	$ 55,246	$ 46,499