CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows provided by operating activities:
Net income (loss)	$ (1,233,000)	$ 1,720,000
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization of property and equipment	677,000	772,000
Amortization of intangibles	6,000	18,000
Stock-based compensation	4,803,000	4,245,000
Allowance for doubtful accounts	2,000	(6,000)
Loss on disposal of equipment	0	10,000
Income from discontinued operations	649,000	0
Changes in operating assets and liabilities:
Accounts and other receivables	(2,037,000)	1,524,000
Deferred income taxes	(1,228,000)	10,417,000
Prepaid income taxes	493,000	(7,495,000)
Prepaid expenses and other current assets	(205,000)	(2,177,000)
Other operating assets	(258,000)	(24,000)
Accounts payable	1,768,000	870,000
Accrued compensation and other current liabilities	(342,000)	1,169,000
Deferred revenue	25,899,000	1,041,000
Other long-term liabilities	(173,000)	240,000
Net cash provided by operating activities	27,523,000	12,324,000
Cash flows provided by investing activities:
Purchases of short-term investments	(25,360,000)	(28,972,000)
Proceeds from maturities of short-term investments	32,500,000	38,000,000
Purchases of property and equipment	(169,000)	(4,383,000)
Proceeds from discontinued operations	1,000,000	0
Net cash provided by investing activities	7,971,000	4,645,000
Cash flows provided by financing activities:
Issuance of common stock under employee stock purchase plan	307,000	367,000
Exercise of stock options	1,889,000	1,451,000
Purchase of treasury stock	(729,000)	0
Net cash provided by financing activities	1,467,000	1,818,000
Net increase in cash and cash equivalents	36,961,000	18,787,000
Cash and cash equivalents:
Beginning of period	25,013,000	14,380,000
End of period	61,974,000	33,167,000
Supplemental disclosure of cash flow information
Cash paid (received) for taxes	(427,000)	136,000
Supplemental disclosure of noncash operating, investing, and financing activities
Amounts accrued for property and equipment	5,000	30,000
Release of Restricted Stock Units and Awards under company stock plan	$ 1,945,000	$ 2,771,000