STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 682,173	$ 693,931
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	568,791	489,206
Amortization	53,314	54,653
Stock based compensation	13,907	17,818
Net gain on sale of vehicles and equipment exchange	(13,979)	(7,163)
Loss on intangible asset abandonment		23,122
Deferred income taxes	153,000	30,000
Changes in working capital components:
Trade receivables	9,459	120,635
Inventories	123,922	(444,030)
Prepaid expenses and other assets	21,296	(42,060)
Income tax refund receivable	(16,400)	59,322
Accounts payable	(61,628)	44,390
Accrued liabilities	(4,766)	58,074
Income taxes payable	(62,557)	84,052
Net cash provided by operating activities	1,466,532	1,181,950
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(762,537)	(566,519)
Proceeds from sale of equipment and vehicles	35,507	59,500
Purchases of intangibles	(70,604)	(56,770)
Purchases of short-term investments	(1,814,878)	(1,857,990)
Proceeds from sale of short-term investments	1,792,939	2,250,054
Net cash used in investing activities	(819,573)	(171,725)
CASH FLOWS FROM FINANCING ACTIVITIES:
Cash dividend paid		(1,998,475)
Proceeds from exercise of stock options	89,398	89,028
Net cash provided by (used in) financing activities	89,398	(1,909,447)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	736,357	(899,222)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	967,943	1,867,165
CASH AND CASH EQUIVALENTS AT END OF YEAR	1,704,300	967,943
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for income taxes, net of refunds received of $13,026 and $61,650, respectively	$ 171,139	$ 177,626