STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 1,511,176	$ 3,206,081	$ 3,805,210
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,730,306	1,050,281	872,171
Deferred income taxes	105,166	1,398,711	416,684
Stock compensation expense	673,855	608,645	538,304
Changes in operating assets and liabilities:
Accounts receivable	539,368	290,731	251,904
Prepaid expenses, other current assets and income tax receivable	609,029	(1,185,641)	353,389
Accounts payable	(97,780)	334,521	(159,239)
Accrued expenses	(491,283)	(1,246,096)	(126,876)
Net cash provided by operating activities	4,579,837	4,457,233	5,951,547
CASH FLOWS FROM INVESTING ACTIVITIES:
Increase in long-term assets; capitalized patent costs	(45,573)	(243,704)	(226,130)
Purchases of property and equipment and capitalized software development costs	(1,752,583)	(7,564,676)	(1,531,632)
Net cash used in investing activities	(1,798,156)	(7,808,380)	(1,757,762)
CASH FLOWS FROM FINANCING ACTIVITIES:
Dividends paid	(3,242,020)	(3,212,267)	(3,178,909)
Proceeds from stock options and tax withholding related to vested shares from employee stock plans	(106,037)	(43,028)	(110,149)
Proceeds from equipment financing	1,098,539	6,999,626	0
Payments of equipment financing	(1,454,852)	(751,543)	0
Net cash (used in) provided by financing activities	(3,704,370)	2,992,788	(3,289,058)
Net (decrease) increase in cash and cash equivalents	(922,689)	(358,359)	904,727
Cash and cash equivalents, beginning of year	3,612,153	3,970,512	3,065,785
Cash and cash equivalents, end of year	2,689,464	3,612,153	3,970,512
Supplemental Disclosures of Cash Flow Information:
Cash paid for income taxes	39,813	1,167,920	1,233,000
Cash paid for interest	128,250	77,046	0
Non-cash investing and financing activities:
Issuance of restricted stock awards	199	260	185
Exercise of stock options	60,394	32,722	20,817
Purchases of equipment through accrued liabilities	$ 337,582	$ 149,509	$ 1,161,255