CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows used in operating activities:
Net loss	$ (27,710)	$ (8,251)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization of property and equipment	469	448
Amortization of intangibles	0	5
Stock-based compensation	2,735	3,589
Deferred income taxes	(77)	(6,472)
Allowance for doubtful accounts	6	2
Income from discontinued operations	0	(649)
Changes in operating assets and liabilities:
Accounts and other receivables	(1,959)	(460)
Prepaid income taxes	0	1,998
Prepaid expenses and other current assets	(112)	(150)
Intangibles and other assets	(99)	(103)
Accounts payable	4,286	1,935
Accrued compensation and other current liabilities	(2,902)	(1,056)
Deferred revenue	(2,929)	(2,107)
Other long-term liabilities	(50)	(217)
Net cash used in operating activities	(28,342)	(11,488)
Cash flows provided by investing activities:
Purchases of short-term investments	(15,879)	(19,886)
Proceeds from maturities of short-term investments	20,000	24,000
Purchases of property and equipment	(110)	(110)
Proceeds for discontinued operations	0	1,000
Net cash provided by investing activities	4,011	5,004
Cash flows provided by financing activities:
Issuance of common stock under employee stock purchase plan	175	128
Exercise of stock options	443	1,677
Net cash provided by financing activities	618	1,805
Net decrease in cash and cash equivalents	(23,713)	(4,679)
Cash and cash equivalents:
Beginning of period	56,865	25,013
End of period	33,152	20,334
Supplemental disclosure of cash flow information
Cash paid (received) for taxes	111	(473)
Supplemental disclosure of noncash operating, investing, and financing activities
Amounts accrued for property and equipment	3	8
Release of Restricted Stock Units and Awards under company stock plan	$ 2,451	$ 1,945