Consolidated Statements of Cash Flows (unaudited) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 1,353,084	$ 742,390
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	16,081	12,945
Stock-based compensation expense	26,400	39,806
Deferred tax assets	18,831	260,413
Changes in operating assets and liabilities:
Accounts receivable	2,172,214	1,389,545
Prepaid expenses and other current assets	(214,129)	(69,095)
Accounts payable and accrued expenses	253,070	1,833,233
Accrued taxes payable	332,924	0
Deferred revenue	(44,881)	(109,275)
Net cash provided by operating activities	3,913,594	4,099,962
Cash flows from investing activities:
Maturity of marketable investments	3,200,000	2,000,000
Purchases of marketable investments	(3,042,964)	(2,000,000)
Payment for royalty buy down	0	(1,500,000)
Net cash provided by (used in) investing activities	157,036	(1,500,000)
Cash flows from financing activities:
Proceeds from stock option exercises	0	78,000
Payments for repurchase of common stock	(205,949)	(198,861)
Excess tax benefits from share-based payment arrangements	0	102,104
Net cash used in financing activities	(205,949)	(18,757)
Increase in cash and cash equivalents	3,864,681	2,581,205
Cash and cash equivalents at beginning of year	3,383,737	3,196,831
Cash and cash equivalents at end of period	7,248,418	5,778,036
Cash paid during the year for:
Interest	0	0
Taxes	$ 378,500	$ 0