Statements of Cash Flows (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash flows from operating activities:
Net income	$ 4,564	$ 2,880
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization, property and equipment	309	295
Amortization, intangibles	54	32
Stock-based compensation	1,981	1,505
Net loss from joint ventures	1,235	1,018
Deferred income tax benefit	(2,433)
Tax benefit from stock-based awards	501
Excess tax benefit from stock-based compensation	(501)
Changes in operating assets and liabilities:
Trade accounts receivable, net	635	1,177
Other current assets	296	(146)
Other assets, net	4	(20)
Accounts payable and other accrued liabilities	(45)	(519)
Deferred revenue	(412)	(346)
Net cash provided by operating activities	6,188	5,876
Cash flows from investing activities:
Purchase of property and equipment	(357)	(129)
Capitalized patent costs	(293)	(534)
Investments in joint ventures	(1,400)	(1,400)
Sale or maturity of marketable securities	53,768	44,714
Purchase of marketable securities	(43,123)	(49,569)
Net cash provided by (used in) investing activities	8,595	(6,918)
Cash flows from financing activities:
Issuance of common stock	733	8
Purchase of common stock	(17,647)	(25)
Excess tax benefit from stock-based awards	501
Net cash used in financing activities	(16,413)	(17)
Net decrease in cash and cash equivalents	(1,630)	(1,059)
Cash and cash equivalents at beginning of period	6,340	8,884
Cash and cash equivalents at end of period	4,710	7,825
Supplemental disclosure of cash flow information:
Cash paid for income taxes		39
Supplemental schedule of non-cash investing activities:
Stock-based compensation capitalized to patent costs	$ 26	$ 22