Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS PROVIDED BY (USED IN) OPERATING ACTIVITIES:
Net loss including non-controlling interest	$ (4,103)	$ (13,233)	$ (24,861)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	489	1,767	3,350
Lease termination charges	0	3,337	0
Goodwill impairment charges	0	5,698	3,388
Increase (decrease) in allowance for doubtful accounts	6	(19)	(57)
Loss on disposal of Grid business	0	0	254
Loss on disposal and write-down of fixed assets	1	81	5,217
Increase in accrued investment income	(43)	(31)	(32)
Stock-based compensation	746	293	1,197
Adjustment to contingent consideration	(318)	(650)	43
Change in operating assets and liabilities:
Accounts receivable	1,009	(53)	2,536
Inventories	323	409	1,757
Deferred cost of goods sold	(20)	277	209
Other current assets	200	356	1,007
Accounts payable	(558)	(1,309)	(81)
Accrued liabilities	(1,176)	(1,097)	(4,034)
Deferred revenues	340	(707)	(846)
Deferred rent	81	(45)	(35)
Net cash used in operating activities	(3,023)	(4,926)	(10,988)
CASH FLOWS PROVIDED BY (USED IN) INVESTING ACTIVITIES:
Purchases of available-for-sale short-term investments	(23,955)	(16,974)	(28,975)
Proceeds from maturities and sales of available‑for‑sale short‑term investments	29,155	28,852	48,000
Change in other long-term assets	160	(795)	29
Cash paid for acquisition, net of cash acquired	0	0	(924)
Proceeds from divestiture of Grid business, net of transaction costs	0	0	2,144
Capital expenditures	(117)	(306)	(746)
Net cash provided by investing activities	5,243	10,777	19,528
CASH FLOWS PROVIDED BY (USED IN) FINANCING ACTIVITIES:
Principal payments of lease financing obligations	0	(11,278)	(2,064)
Proceeds from exercise of stock options	0	0	17
Restricted investments used as collateral for line of credit	0	0	(6,250)
Repurchase of common stock from employees for payment of taxes on vesting of restricted stock units and upon exercise of stock options	(43)	(153)	(422)
Net cash used in financing activities	(43)	(11,431)	(8,719)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	(65)	(69)	(1,129)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	2,112	(5,649)	(1,308)
CASH AND CASH EQUIVALENTS:
Beginning of period	7,691	13,340	14,648
End of period	9,803	7,691	13,340
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest on lease financing obligations	0	387	1,003
Cash paid for income taxes	169	249	294
Fair value of stock issued in connection with acquisition	0	0	715
Non-cash transfer from financing to investing for restricted investments used as collateral for credit cards	0	0	1,399
Non-cash transfer of restricted investments to available-for-sale short-term investments	$ 151	$ 0	$ 4,851