Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 5,285,847	$ 2,981,075	$ 6,601,626
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	64,323	64,190	50,685
Stock-based compensation expense	111,636	228,485	517,367
Deferred income tax	(10,653)	1,474,904	(3,047,955)
Changes in operating assets and liabilities:
Accounts receivable	77,942	(1,845,443)	(1,250,792)
Prepaid expenses and other current assets	(381,433)	142,160	(65,642)
Accounts payable and accrued expenses	121,411	(242,233)	(3,009,109)
Deferred revenue	(133,524)	(372,705)	(483,769)
Net cash provided by (used in) operating activities from operations	5,135,549	2,430,433	(687,589)
Cash flows from investing activities:
Maturities of marketable securities	9,710,000	5,070,000	5,360,970
Purchases of marketable securities	(11,556,964)	(5,190,000)	(5,000,000)
Payment for royalty buy down	(600,000)	(1,500,000)	0
Net cash provided by (used in) investing activities from operations	(2,446,964)	(1,620,000)	360,970
Cash flows from financing activities:
Proceeds from stock option exercises	30,000	148,425	82,450
Repurchases of common stock	(674,874)	(1,034,647)	(739,551)
Excess tax benefits from share-based payment arrangements	197,412	262,695	1,709,699
Net cash provided by (used in) financing activities from operations	(447,462)	(623,527)	1,052,598
Increase in cash and cash equivalents	2,241,123	186,906	725,979
Cash and cash equivalents at beginning of year	3,383,737	3,196,831	2,470,852
Cash and cash equivalents at end of year	5,624,860	3,383,737	3,196,831
Cash paid during the year for:
Interest	0	0	0
Taxes	$ 2,713,500	$ 232,000	$ 190,000