Organization, Consolidation and Presentation of Financial Statements [Abstract] Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Receivables Receivables, Policy [Policy Text Block] Inventories, net Inventory, Policy [Policy Text Block] Warranty Liability Standard Product Warranty, Policy [Policy Text Block] Revenue Recognition Revenue Recognition, Policy [Policy Text Block] Recently issued accounting pronouncements not yet adopted New Accounting Pronouncements, Policy [Policy Text Block] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Equity [Abstract] Shareholder Rights Plan Preferred Stock [Text Block] Guarantees [Abstract] Schedule of Guarantor Obligations [Table] Schedule of Guarantor Obligations [Table] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Performance Guarantee Performance Guarantee [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Expires June 2017 Letter Of Credit Expiring on June 2017 [Member] Letter Of Credit Expiring on June 2017 [Member] Guarantor Obligations [Line Items] Guarantor Obligations [Line Items] Deposit guarantees outstanding for building lease Deposit guarantees outstanding for building lease Refers to the deposit amount outstanding for building lease. Building lease, renewal term Lessee Leasing Arrangements, Operating Leases, Renewal Term Performance guarantee outstanding deposit for fixed asset Performance guarantee outstanding deposit for fixed asset Performance guarantee outstanding deposit for fixed asset included in restricted cash. Performance guarantees outstanding to customers Guarantor Obligations, Current Carrying Value Statement of Cash Flows [Abstract] Operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net loss Net Income (Loss) Attributable to Parent Adjustments to reconcile net loss to cash used in operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation expense Depreciation Net change to allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Period Increase (Decrease) Loss on disposal of fixed assets Gain (Loss) on Disposition of Property Plant Equipment Stock-based compensation Share-based Compensation Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Restricted cash Increase (Decrease) in Restricted Cash for Operating Activities Accounts receivable Increase (Decrease) in Accounts Receivable Inventories Increase (Decrease) in Inventories Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable Increase (Decrease) in Accounts Payable Accrued expenses Increase (Decrease) in Accrued Liabilities Deferred revenue Increase (Decrease) in Deferred Revenue Long term liabilities Increase (Decrease) in Other Noncurrent Liabilities Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities Investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Taxes paid related to net share settlement of equity awards Payments For Taxes Related To Settlement of Equity Awards The cash outflow associated with the payment of taxes related to the settlement of equity awards. Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Effects of exchange rates on cash Effect of Exchange Rate on Cash and Cash Equivalents Change in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents, end of period Fair Value Disclosures [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Money-market funds, fair value Restricted Cash and Cash Equivalents Earnings Per Share [Abstract] Computation of basic and diluted net loss per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Debt Disclosure [Abstract] Revolving Line of Credit Debt Disclosure [Text Block] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series B Junior Participating Preferred Stock Series B Preferred Stock [Member] Class of Stock [Line Items] Class of Stock [Line Items] Preferred stock, number of shares designated Preferred Stock, Shares Authorized Shareholder rights plan, term extension if plan is ratified before expiration date Class Of Warrant Or Right, Shareholder Rights Plan, Extension, Term Class Of Warrant Or Right, Shareholder Rights Plan, Extension, Term Income Statement [Abstract] Revenues: Revenue, Net [Abstract] Product revenue Sales Revenue, Goods, Net Service and other revenue Sales Revenue, Services, Net Total revenue Revenue, Net Cost of goods sold: Cost of Goods and Services Sold [Abstract] Cost of product revenue Cost of Goods Sold Cost of service and other revenue Cost of Services Total cost of goods sold Cost of Goods and Services Sold Gross profit Gross Profit Operating expenses: Operating Expenses [Abstract] Research and development Research and Development Expense Selling and marketing Selling and Marketing Expense General and administrative General and Administrative Expense Total operating expenses Operating Expenses Loss from operations Operating Income (Loss) Interest expense Interest Expense Other income (expense), net Nonoperating Income (Expense) Net loss Net loss per share, basic and diluted (in usd per share) Earnings Per Share, Basic and Diluted Shares used in computing net loss per share, basic and diluted Weighted Average Number of Shares Outstanding, Basic and Diluted Comprehensive loss: Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Translation loss on subsidiaries denominated in foreign currencies Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Restricted Cash Restricted Cash and Investments [Abstract] Restricted cash Restricted Cash and Cash Equivalents, Current Performance guarantee outstanding deposit for building lease Receivables Receivables [Abstract] Trade receivables Accounts Receivable, Gross, Current Less: Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Accounts receivable, net Accounts Receivable, Net, Current Standard payment term Threshold Period Past Due for Write-off of Trade Accounts Receivable Extended payment term Threshold Period Past Due For Write-Off of Trade Accounts Receivable, Extended Term Threshold Period Past Due For Write-Off of Trade Accounts Receivable, Extended Term Inventory Inventory, Net [Abstract] Inventory adjustments Inventory Adjustments Raw materials Inventory, Raw Materials, Net of Reserves Work in process Inventory, Work in Process, Net of Reserves Finished goods Inventory, Finished Goods, Net of Reserves Inventories, net Inventory, Net Accrued Expenses Accounts Payable and Accrued Liabilities, Current [Abstract] Compensation, severance and benefits Employee-related Liabilities, Current Management incentive bonus Accrued Bonuses, Current Warranty liability Standard Product Warranty Accrual, Current Taxes, other than income Accrual for Taxes Other than Income Taxes, Current Professional fees Accrued Professional Fees, Current Deferred Rent and other Deferred Rent And Other Liabilities, Current Deferred Rent And Other Liabilities, Current Accrued expenses Accrued Liabilities, Current Warranty Liability Warranty Liability [Abstract] Standard power quality products warranty period from date of commissioning Standard power quality products warranty period from date of commissioning The standard power quality products warranty period from date of commissioning. Standard power quality products warranty period from date of shipment Standard power quality products warranty period from date of shipment The standard power quality products warranty period from date of shipment. Standard products warranty period for primary OEM customer Standard products warranty period for primary OEM customer The standard products warranty period from date of shipment to end user for primary OEM customer. Extended products warranty period from date of shipment to primary OEM customer, Maximum Extended products warranty period from date of shipment to primary OEM customer, Maximum The extended maximum products warranty period from date of shipment to primary OEM customer. Changes in warranty liability Movement in Standard Product Warranty Accrual [Roll Forward] Beginning balance Standard Product Warranty Accrual Warranty expense Standard Product Warranty Accrual, Increase for Warranties Issued Payments Standard Product Warranty Accrual, Decrease for Payments Ending balance Warranty liability included in accrued expenses Warranty liability included in long-term liabilities Standard Product Warranty Accrual, Noncurrent Balance at period end Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Statement, Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Treasury Stock Treasury Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Accumulated Deficit Retained Earnings [Member] Other Accumulated Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance Stockholders' Equity Attributable to Parent Balance (in shares) Shares, Outstanding Release of Restricted Stock Stock Issued During Period, Value, Restricted Stock Award, Gross Release of Restricted Stock (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Shares held in treasury Adjustments Related to Tax Withholding for Share-based Compensation Shares held in treasury (in shares) Shares Paid for Tax Withholding for Share Based Compensation Net translation loss on foreign subsidiaries Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Net loss Balance Balance (in shares) Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Accounts receivable, net of allowance for doubtful accounts of $37 and $70 at June 30, 2016 and December 31, 2015, respectively Inventories, net Prepaid expenses and other Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property and equipment, net Property, Plant and Equipment, Net Deposits and other Other Assets, Noncurrent Total assets Assets LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued expenses Deferred revenue Deferred Revenue, Current Revolving line of credit Line of Credit, Current Total current liabilities Liabilities, Current Long-term liabilities Other Liabilities, Noncurrent Commitments and contingencies Commitments and Contingencies Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock - $0.001 par value; 2,000 shares authorized Preferred Stock, Value, Issued Common stock - $0.001 par value; 40,000 shares authorized; 23,177 and 23,171 shares issued and 23,114 and 23,109 shares outstanding at June 30, 2016 and December 31, 2015, respectively Common Stock, Value, Issued Treasury stock Treasury Stock, Value Additional paid-in capital Additional Paid in Capital, Common Stock Accumulated deficit Retained Earnings (Accumulated Deficit) Other accumulated comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Total liabilities and stockholders’ equity Liabilities and Equity Net Loss Per Share Earnings Per Share [Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Line of Credit Facility [Table] Line of Credit Facility [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Line of Credit Revolving Credit Facility [Member] Letter of Credit Letter of Credit [Member] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] U.K. and Germany U.K. And Germany [Member] U.K. And Germany [Member] Lender Name [Axis] Lender Name [Axis] Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] Silicon Valley Bank Silicon Valley Bank [Member] Silicon Valley Bank [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Prime Rate Prime Rate [Member] Line of Credit Facility Inventory Borrowing Rates [Line Items] Line of Credit Facility [Line Items] Maximum borrowing capacity, percentage Line of credit facility maximum borrowing capacity percentage Percentage for line of credit facility maximum borrowing capacity. Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Current borrowing capacity Line of Credit Facility, Current Borrowing Capacity Borrowing base sublimits, purchase orders Borrowing Base Sublimits, Purchase Orders Borrowing Base Sublimits, Purchase Orders Borrowing base sublimits, inventory Borrowing Base Sublimits, Inventory Borrowing Base Sublimits, Inventory Borrowing base sublimits, accounts receivable Borrowing Base Sublimits, Accounts Receivable Borrowing Base Sublimits, Accounts Receivable Liquidity ratio for reconciliation period Liquidity Ratio for reconciliation period Liquidity Ratio for immediate reconciliation period. Number of reconciliation periods used to evaluate sublimits Debt Instrument, Borrowing Base Sublimits, Number Of Reconciliation Periods Debt Instrument, Borrowing Base Sublimits, Number Of Reconciliation Periods Minimum prime rate Debt Instrument, Interest Rate, Stated Percentage Basis spread on prime rate Debt Instrument, Basis Spread on Variable Rate Liquidity ratio, borrowing base eligibility threshold Debt Instrument, Liquidity Ratio, Borrowing Base Eligibility Threshold Debt Instrument, Liquidity Ratio, Borrowing Base Eligibility Threshold Liquidity ratio, borrowing base eligibility threshold, minimum evaluation period Debt Instrument, Liquidity Ratio, Borrowing Base Eligibility Threshold, Minimum Evaluation Period Debt Instrument, Liquidity Ratio, Borrowing Base Eligibility Threshold, Minimum Evaluation Period Restrictive covenant, CEO or CFO replacement restriction, number of days Debt Instrument, Restrictive Covenant, Key Executive Replacement Restriction, Number Of Days Debt Instrument, Restrictive Covenant, Key Executive Replacement Restriction, Number Of Days Minimum liquidity ratio requirement Minimum Liquidity Ratio Requirement Minimum Liquidity Ratio Requirement Increase in rate on finance charges or interest rates as applicable, in event of default Increase In Rate On Finance Charges Or Interest Rates As Applicable In Event Of Default Increase In Rate On Finance Charges Or Interest Rates, As Applicable, In Event Of Default Increase in rate on collateral handling fees in event of default Increase In Rate On Collateral Handling Fees In Event Of Default Increase In Rate On Collateral Handling Fees In Event Of Default Line of credit facility outstanding Long-term Line of Credit Line of credit facility, amount available for use Line of Credit Facility, Remaining Borrowing Capacity Guarantees Guarantees [Text Block] Basic and dilutive: Earnings Per Share, Basic and Diluted [Abstract] Weighted-average shares of common stock outstanding used in computing basic and diluted net loss per share Weighted Average Number of Shares Outstanding, Basic Basic and diluted net loss per share (in usd per share) Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Stock Options Employee Stock Option [Member] Restricted Stock Units (RSUs) Restricted Stock [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Common stock equivalents excluded from calculation because effect would have been anti-dilutive (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Basis of Presentation Business Description and Basis of Presentation [Text Block] ASSETS Current assets: Accounts receivable, allowance for doubtful accounts Stockholders' equity: Preferred stock, par value (in usd per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Common stock, par value (in usd per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Accounts receivables Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Schedule of inventory Schedule of Inventory, Current [Table Text Block] Schedule of accrued expenses Schedule of Accrued Liabilities [Table Text Block] Changes in warranty liability Schedule of Product Warranty Liability [Table Text Block] Revenue Recognition, Multiple-deliverable Arrangements [Table] Revenue Recognition, Multiple-deliverable Arrangements [Table] Revenue Recognition, Multiple-deliverable Arrangements [Line Items] Revenue Recognition, Multiple-deliverable Arrangements [Line Items] Number of CleanSource UPS or PowerHouse products included in significant MEAs Number Of First Tier Products Included In Significant MEAs Number of products included in the entity's most significant MEAs related to first tier products. Number of second tier products included in significant MEAs Number Of Second Tier Products Included In Significant MEAs The number of products included in the entity's most significant multiple element arrangements (MEAs) related to second tier products. Second tier products include design services, project management, commissioning and installation services, spare parts or consumables, and extended maintenance agreements. Commissioning and installation period Commissioning and installation period Under a multiple element arrangement, the typical period subsequent to product delivery during which commissioning and installation takes place. Maintenance agreements, consumables, repair, maintenance and consulting services general deliverable period Maintenance Agreements, Consumables, Repair, Maintenance And Consulting Services, General Deliverable Period Maintenance Agreements, Consumables, Repair, Maintenance And Consulting Services, General Deliverable Period Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Schedule of Product Information [Table] Schedule of Product Information [Table] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Product Revenue Sales Revenue, Net [Member] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] UPS Systems UPS Systems [Member] UPS Systems [Member] MIS Products MIS Products [Member] MIS Products [Member] Product Information [Line Items] Product Information [Line Items] Product revenue, in percentage Concentration Risk, Percentage Significant Accounting Policies and Supplemental Balance Sheet Information Significant Accounting Policies and Supplemental Balance Sheet Information [Text Block] The entire disclosure for all significant accounting policies of the reporting entity and for supplemental balance sheet disclosures, including descriptions and amounts for assets, liabilities, and equity.