CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities:
Net loss	[1]	$ (15,956)	$ (27,041)	$ (3,483)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation expense		1,987	2,914	2,874
Amortization of intangible assets and other		1,028	1,069	1,091
Amortization of premiums and accretion of discounts on investments		284	467	726
Depreciation		720	324	275
Goodwill impairment		0	14,240	0
Deferred income taxes		17	(1,167)	326
Loss on disposal of fixed assets		124	0	0
Changes in operating assets and liabilities:
Accounts receivable, net		452	4,608	(634)
Prepaid expenses and other current assets		264	(73)	(82)
Other assets		(83)	141	(80)
Accounts payable		818	(1,358)	764
Accrued compensation		(305)	485	634
Other accrued liabilities		(1,126)	589	(331)
Other long-term liabilities		(253)	(261)	10
Deferred revenue		579	(405)	(632)
Net cash provided by (used in) operating activities		(11,450)	(5,468)	1,458
Investing activities:
Purchases of property and equipment		(561)	(1,896)	(231)
Purchases of investments		(28,610)	(37,695)	(63,510)
Maturities of investments		29,993	49,493	56,275
Net cash provided by (used in) investing activities		822	9,902	(7,466)
Financing activities:
Utilized excess tax benefit		0	0	(8)
Proceeds from issuances of common stock		86	157	1,096
Repurchase of common stock		(128)	(131)	0
Net cash provided by (used in) financing activities		(42)	26	1,088
Net (decrease) increase in cash and cash equivalents		(10,670)	4,460	(4,920)
Effect of exchange rate changes on cash and cash equivalents		(38)	(216)	(116)
Cash and cash equivalents at beginning of year		27,598	23,354	28,390
Cash and cash equivalents at end of year		16,890	27,598	23,354
Supplemental schedule of cash flow information:
Cash paid for income taxes		$ 170	$ 193	$ 225

[1] Prior periods adjusted to reflect the impact of the one-for-three reverse stock split that became effective on January 20, 2017, as discussed in Note 1.