Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net income	$ 4,088,104	$ 1,331,955
Adjustments to reconcile net income to net cash provided By operating activities:
Amortization	319,582	108,595
Stock-based compensation expense	38,830	10,708
Deferred tax expense	240,628	30,742
Gain on the sale of fixed assets	0	(1,150)
Changes in operating assets and liabilities:
Accounts receivable	(63,244)	2,959,252
Income tax receivable	(55,121)	(1,016,778)
Investment interest receivable	(71,066)	2,549
Prepaid expenses	(258,189)	35,078
Patent costs	(17,381)	(151,454)
Accounts payable and accrued expenses	287,693	84,917
Deferred revenue	(24,689)	(34,565)
Net cash provided by operating activities	4,485,147	3,359,849
Cash flows from investing activities:
Maturity of marketable investments	8,302,605	4,811,964
Purchases of marketable investments	(16,933,286)	(5,638,002)
Proceeds from sale of fixed asset	0	1,150
Net cash used in investing activities	(8,630,681)	(824,888)
Cash flows from financing activities:
Proceeds from stock option exercises	1,672,973	169,000
Payments for repurchase of common stock	(701,121)	(750,598)
Excess tax benefits from share-based payment arrangements	1,910,065	1,262,483
Net cash provided by financing activities	2,881,917	680,885
(Decrease) increase in cash and cash equivalents	(1,263,617)	3,215,846
Cash and cash equivalents at beginning of year	9,810,816	5,624,860
Cash and cash equivalents at end of period	8,547,199	8,840,706
Cash paid during the year for:
Interest	0	0
Taxes	$ 80,000	$ 415,000