CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 4,494,316	$ 2,415,416
Marketable securities, current	451,357	5,495,556
Trade accounts receivable, less allowance for doubtful accounts of $303,656 in 2013 and $303,839 in 2012	11,167,814	10,407,649
Other receivables	240,751	244,081
Inventories	7,002,238	6,344,982
Prepaid income taxes	351,652	279,964
Prepaid expenses, other	1,035,647	799,124
Deferred income taxes	1,280,526	926,081
Total current assets	26,024,301	26,912,853
Marketable securities, noncurrent		210,440
Property, plant and equipment, net of accumulated depreciation of $7,516,707 in 2013 and $6,876,028 in 2012	5,738,650	5,350,310
Goodwill	8,901,744	8,729,438
Investment in affiliated company	3,380,000	3,303,750
Intangible assets, net	12,596,514	12,381,614
Other assets	279,360	308,996
Deferred income taxes	137,471	22,370
TOTAL ASSETS	57,058,040	57,219,771
Current liabilities:
Current maturities of long-term notes payable	2,624,889	2,566,154
Revolving lines of credit	2,550,000	5,327,515
Accounts payable	3,884,483	2,893,225
Compensation and related expenses	3,318,941	3,510,272
Other accrued expenses	862,460	868,199
Accrued product warranties	241,318	240,621
Accrued income taxes	501,320	36,139
Dividends payable	610,404	579,386
Deferred revenue	863,592	472,185
Total current liabilities	15,457,407	16,493,696
Notes payable	2,433,517	3,926,863
Obligations to former employees	77,910	76,161
Deferred income taxes	2,395,361	2,576,396
Accrued income taxes	296,949	265,207
Total noncurrent liabilities	5,203,737	6,844,627
Total liabilities	20,661,144	23,338,323
Stockholders' equity:
Capital stock - undesignated. Authorized 3,000,000 shares; none issued and outstanding in 2013 and 2012
Common stock - $0.10 par value. Authorized 22,000,000 shares; issued and outstanding 5,549,129 shares in 2013 and 5,517,966 shares in 2012	554,913	551,797
Additional paid-in capital	4,402,003	3,738,968
Retained earnings	31,415,665	30,217,977
Accumulated other comprehensive loss	24,315	(627,294)
Total stockholders' equity	36,396,896	33,881,448
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 57,058,040	$ 57,219,771