Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income	$ 4,645,960	$ 5,285,847	$ 2,981,075
Adjustments to reconcile net income to net cash provided in operating activities:
Amortization	247,097	64,323	64,190
Stock-based compensation expense	21,416	111,636	228,485
Deferred tax expense	429,005	(10,653)	1,474,904
Gain on the sale of fixed assets	(1,150)	0	0
Changes in operating assets and liabilities:
Accounts receivable	2,017,371	77,942	(1,845,443)
Income tax receivable	(397,408)	(204,638)	193,650
Prepaid expenses and other current assets	115,672	(176,795)	(51,490)
Patent costs	(198,952)	0	(154,096)
Accounts payable and accrued expenses	(90,580)	121,411	(88,137)
Deferred royalty buy-down	(600,000)	(600,000)	(1,500,000)
Deferred revenue	(59,255)	(133,524)	(372,705)
Net cash provided by operating activities from operations	6,129,176	4,535,549	930,433
Cash flows from investing activities:
Maturities of marketable securities	7,646,964	9,710,000	5,070,000
Purchases of marketable securities	(12,848,374)	(11,556,964)	(5,190,000)
Proceeds from sale of fixed assets	1,150	0	0
Net cash used in investing activities from operations	(5,200,260)	(1,846,964)	(120,000)
Cash flows from financing activities:
Proceeds from stock option exercises	2,146,821	30,000	148,425
Repurchases of common stock	(829,613)	(674,874)	(1,034,647)
Excess tax benefits from share-based payment arrangements	1,939,832	197,412	262,695
Net cash provided by (used in) financing activities from operations	3,257,040	(447,462)	(623,527)
Increase in cash and cash equivalents	4,185,956	2,241,123	186,906
Cash and cash equivalents at beginning of year	5,624,860	3,383,737	3,196,831
Cash and cash equivalents at end of year	9,810,816	5,624,860	3,383,737
Cash paid during the year for:
Interest	0	0	0
Taxes	$ 415,279	$ 2,713,500	$ 232,000