Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 1,091,745	$ 934,166
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	530,819	492,286
GainLossOnDispositionOfAssets	(42,486)	(57,500)
Deferred income taxes	(80,000)	(26,000)
Changes in operating assets and liabilities:
Accounts receivable, net	(1,223,208)	(1,022,466)
Inventories, net	(55,880)	(15,438)
Other current assets	154,201	102,359
Accounts payable	280,255	300,212
Accrued wages and salaries	345,754	319,373
Other accrued expenses	165,409	(54,324)
Unearned revenue and customer deposits	112,706	(102,490)
Net cash provided by operating activities	1,279,315	870,178
Cash flows from investing activities:
Capital expenditures	(1,775,255)	(432,848)
Proceeds from the sale of equipment	90,200	57,500
Proceeds from certificates of deposit	4,765,000	2,244,000
Purchases of certificates of deposit	(3,585,248)	(2,551,000)
Net cash used in investing activities	(505,303)	(682,348)
Cash flows from financing activities:
Cash dividends paid	(289,839)	(289,839)
Net cash used in financing activities	(289,839)	(289,839)
Net increase (decrease) in cash and cash equivalents	484,173	(102,009)
Cash and Cash Equivalents, at Carrying Value, Beginning Balance	392,810	704,345
Cash and Cash Equivalents, at Carrying Value, Ending Balance	876,983	602,336
Supplemental schedule of non-cash investing activities:
Capital expenditures in accounts payable	$ 199,694	$ 80,558