CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows provided by (used in) operating activities:
Net income (loss)	$ (8,251)	$ 1,536
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization of property and equipment	448	549
Amortization of intangibles	5	15
Stock-based compensation	3,589	2,969
Allowance for doubtful accounts	2	3
Loss on sale disposal of equipment	0	10
Income from discontinued operations	649	0
Changes in operating assets and liabilities:
Accounts and other receivables	(460)	1,918
Deferred income taxes	(6,472)	4,766
Prepaid income taxes	1,998	(3,718)
Prepaid expenses and other current assets	(150)	(1,289)
Other operating assets	(103)	(22)
Accounts payable	1,935	573
Accrued compensation and other current liabilities	(1,056)	1,277
Deferred revenue	(2,107)	7,895
Other long-term liabilities	(217)	192
Net cash provided by (used in) operating activities	(11,488)	16,674
Cash flows provided by investing activities:
Purchases of short-term investments	(19,886)	(4,994)
Proceeds from maturities of short-term investments	24,000	29,000
Purchases of property and equipment	(110)	(3,289)
Proceeds from discontinued operations	1,000	0
Net cash provided by investing activities	5,004	20,717
Cash flows provided by financing activities:
Issuance of common stock under employee stock purchase plan	128	190
Exercise of stock options	1,677	675
Net cash provided by financing activities	1,805	865
Net increase (decrease) in cash and cash equivalents	(4,679)	38,256
Cash and cash equivalents:
Beginning of period	25,013	14,380
End of period	20,334	52,636
Supplemental disclosure of cash flow information
Cash paid for taxes	(473)	90
Supplemental disclosure of noncash operating, investing, and financing activities
Amounts accrued for property and equipment	8	1,052
Release of Restricted Stock Units and Awards under company stock plan	$ 1,945	$ 2,647