CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities
Net loss	$ (6,976)us-gaap_NetIncomeLoss	$ (11,109)us-gaap_NetIncomeLoss
Items not affecting cash flows
Depreciation and amortization	1,025us-gaap_DepreciationAndAmortization	1,141us-gaap_DepreciationAndAmortization
Stock-based compensation	1,872us-gaap_ShareBasedCompensation	2,800us-gaap_ShareBasedCompensation
Change in fair value of warrants	0us-gaap_UnrealizedGainLossOnDerivatives	1,076us-gaap_UnrealizedGainLossOnDerivatives
Exchange rate loss, net	226	20
Changes in current assets and liabilities
Decrease in other current assets	120	139
Increase (decrease) in payables and accruals	231	(2,560)
Net cash used in operating activities	(3,502)	(8,493)
Cash flows from investing activities
Acquisition of property and equipment	0	(72)
Increase in deposits	(278)	0
Net cash used in investing activities	(278)	(72)
Cash flows from financing activities
Exercise of stock options	0us-gaap_ProceedsFromStockPlans	1,531us-gaap_ProceedsFromStockPlans
Exercise of warrants	0us-gaap_ProceedsFromWarrantExercises	1,265us-gaap_ProceedsFromWarrantExercises
Cash provided by financing activities	0	2,796
Effect of exchange rate changes on cash and cash equivalents	(4)	1
Decrease in cash and cash equivalents	(3,784)	(5,768)
Cash and cash equivalents at beginning of period	16,023	33,586
Cash and cash equivalents at end of period	12,239	27,818
Non-cash investing and financing transactions
Non-cash acquisition of cost method investment	0	787
Conversion of derivative warrants into common stock	0	746
Change in classification of derivative warrants to equity warrants	$ 175	$ 0

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.