Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets
Cash	$ 2,198	$ 1,364
Investment securities, available-for-sale, at fair value	1,162	1,176
Accounts receivable, net
Trade - billed (less allowance for doubtful accounts of $350 and $333), including contract retentions	9,444	12,723
Trade - unbilled	956	310
Inventories, net
Raw materials	597	488
Finished goods	1,574	1,754
Prepaid expenses and other assets	708	784
Refundable income taxes	464	432
Total current assets	17,103	19,031
Property and equipment, net	17,998	17,735
Deferred buy-back lease asset, net	4,861	5,042
Other assets	337	307
Total assets	40,299	42,115
Current liabilities
Accounts payable - trade	2,669	3,180
Accrued expenses and other liabilities	94	125
Deferred revenue	1,744	1,891
Accrued compensation	761	1,075
Dividend payable	0	282
Deferred buy-back lease obligation	1,037	966
Operating lease liabilities	81	81
Current maturities of notes payable	847	925
Customer deposits	492	1,077
Total current liabilities	7,725	9,602
Deferred revenue	117	241
Deferred buy-back lease obligation	4,853	5,183
Operating lease liabilities	275	296
Notes payable - less current maturities	4,660	4,086
Deferred tax liability	1,902	1,886
Total liabilities	19,532	21,294
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; 5,224,911 and 5,224,911 issued and 5,183,991 and 5,164,324 outstanding, respectively	52	52
Additional paid-in capital	6,242	6,242
Treasury stock, at cost, 40,920 shares	(102)	(102)
Other	(26)	(10)
Retained earnings	14,601	14,639
Total stockholders' equity	20,767	20,821
Total liabilities and stockholders' equity	$ 40,299	$ 42,115