Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Financial Statement Presentation	Financial Statement Presentation The accompanying condensed consolidated financial statements include the accounts of Maxwell Technologies, Inc. and its subsidiaries and have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). All intercompany transactions and account balances have been eliminated in consolidation. The Company has prepared the accompanying unaudited interim condensed consolidated financial statements in accordance with the instructions to Form 10-Q and the standards of accounting measurement set forth in the Interim Reporting Topic of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”). Consequently, the Company has not necessarily included in this Form 10-Q all information and footnotes required for audited financial statements. In the opinion of the Company’s management, the accompanying unaudited condensed consolidated financial statements in this Form 10-Q contain all adjustments (consisting only of normal recurring adjustments, except as otherwise indicated) necessary to present fairly the financial position, results of operations, and cash flows of Maxwell Technologies, Inc. for all periods presented. The results reported in these condensed consolidated financial statements should not be regarded as necessarily indicative of results that may be expected for any subsequent period or for the entire year. These unaudited condensed consolidated financial statements and notes thereto should be read in conjunction with the Company’s audited financial statements and the notes thereto included in the Company’s latest Annual Report on Form 10-K. Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with U.S. GAAP have been condensed or omitted in the accompanying interim consolidated financial statements. The year-end condensed balance sheet data was derived from audited financial statements, but does not include all disclosures required by U.S. GAAP.
Reclassifications	Reclassifications Foreign currency exchange gains and losses have been reclassified from "cost of revenue" and "selling, general and administrative" expenses to "foreign currency exchange gains and losses, net" in the condensed consolidated statement of operations for the three and nine months ended September 30, 2014 to conform to the current period presentation. These reclassifications do not impact reported net loss and do not otherwise have a material impact on the presentation of the overall financial statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect reported amounts and related disclosures. These estimates include, but are not limited to, assessing the collectability of accounts receivable, applied and unapplied production costs, production capacities, the usage and recoverability of inventories and long-lived assets, including deferred income taxes, the incurrence of warranty obligations, impairment of goodwill and other intangible assets, estimation of the cost to complete certain projects, accruals for estimated losses from legal matters, and estimation of the value of stock-based compensation awards, including the probability that the performance criteria of restricted stock awards will be met.
Income Taxes	Income Taxes At September 30, 2015, the Company has a cumulative valuation allowance recorded offsetting its worldwide net deferred tax assets of $64.2 million, of which the significant majority represents the valuation allowance on its U.S. net deferred tax asset. The Company has established a valuation allowance against its U.S. federal and state deferred tax assets due to the uncertainty surrounding the realization of such assets. Management periodically evaluates the recoverability of the deferred tax assets and at such time as it is determined that it is more likely than not that U.S. deferred tax assets are realizable, the valuation allowance will be reduced accordingly. Any such release would result in recording a tax benefit that would increase net income in the period the valuation is released. The Company records taxes on the undistributed earnings of foreign subsidiaries unless the subsidiaries’ earnings are considered indefinitely reinvested outside of the U.S. As a result of changes in business circumstances, the Company changed its estimate of the amount of foreign subsidiary earnings considered permanently reinvested, and recorded a deferred tax liability in 2014 for Swiss withholding taxes of $1.6 million associated with $31.8 million of undistributed earnings of our Swiss subsidiary that were no longer considered indefinitely reinvested. In June 2015, based on revisions to the Company's long term plans, the Company again changed its estimate of the amount of foreign earnings considered permanently reinvested. Therefore, in the quarter ended June 30, 2015, the Company recorded an additional deferred tax liability for Swiss withholding taxes of $2.1 million associated with an additional $41.7 million of undistributed earnings of our Swiss subsidiary that are no longer considered indefinitely reinvested. In the event that the Company repatriates these funds, these withholding taxes would become payable.
Warranty Obligation	Warranty Obligation The Company provides warranties on all product sales for terms ranging from one to eight years. The Company accrues for the estimated warranty costs at the time of sale based on historical warranty experience plus any known or expected changes in warranty exposure.
Revenue Recognition	Revenue Recognition Revenue is derived primarily from the sale of manufactured products directly to customers. Product revenue is recognized, according to the guidelines of the Securities and Exchange Commission (“SEC”) Staff Accounting Bulletin (“SAB”) Numbers 101, Revenue Recognition in Financial Statements, and 104, Revenue Recognition, when all of the following criteria are met: (1) persuasive evidence of an arrangement exists (upon contract signing or receipt of an authorized purchase order from a customer); (2) title passes to the customer at either shipment from the Company’s facilities or receipt at the customer facility, depending on shipping terms; (3) customer payment is deemed fixed or determinable and free of contingencies or significant uncertainties; and (4) collectability is reasonably assured. This policy has been consistently applied from period to period. Revenue is not recognized for sales that do not meet the revenue recognition criteria at the time of sale. Revenue is recognized once all of the criteria for revenue recognition are determined to have been met. For example, if the Company does not believe that collection of the sales price is reasonably assured at the time of sale, it defers revenue recognition until cash is received. If the Company receives cash payment from the customer prior to the achievement of the revenue recognition criteria, the amount received from the customer is recorded as deferred revenue in the consolidated balance sheets. Total deferred revenue and customer deposits in the consolidated balance sheets as of September 30, 2015 and December 31, 2014 was $1.2 million and $703,000, respectively, and relates to cash received from customers on sales for which the revenue recognition criteria had not been achieved, customer advances, as well as other less significant customer arrangements requiring the deferral of revenue. Revenue from production-type contracts, which represent less than five percent of total revenue, is recognized using the percentage of completion method. The degree of completion is determined based on costs incurred, excluding costs that are not representative of progress to completion, as a percentage of total costs anticipated.
Revenue recognition from production type contracts	Revenue from production-type contracts, which represent less than five percent of total revenue, is recognized using the percentage of completion method. The degree of completion is determined based on costs incurred, excluding costs that are not representative of progress to completion, as a percentage of total costs anticipated.
Liquidity	Liquidity As of September 30, 2015, the Company had approximately $24.8 million in cash and cash equivalents, and working capital of $65.5 million. In July 2015, the Company entered into a loan agreement with East West Bank (“EWB”), whereby EWB made available to the Company a secured credit facility in the form of a revolving line of credit which is available up to a maximum of the lesser of: (a) $25.0 million; or (b) a certain percentage of domestic and foreign trade receivables. As of September 30, 2015, there were no drawings under this revolving line of credit and the amount available was $20.4 million. Management believes the available cash balance, along with the available borrowings under the revolving line of credit, will be sufficient to fund operations, obligations as they become due, and capital investments for at least the next twelve months.
Net Loss per Share	Net Loss per Share In accordance with the Earnings Per Share Topic of the FASB ASC, basic net income (loss) per share is calculated using the weighted average number of common shares outstanding during the period. Diluted net income per share includes the impact of additional common shares that would have been outstanding if potentially dilutive common shares were issued. Potentially dilutive securities are not considered in the calculation of diluted net loss per share, as their inclusion would be anti-dilutive.
Restructuring and Exit Costs	Restructuring and Exit Costs Restructuring and exit costs involve employee-related termination costs, facility exit costs and other costs associated with restructuring activities. The Company accounts for charges resulting from operational restructuring actions in accordance with ASC Topic 420, Exit or Disposal Cost Obligations (“ASC 420”) and ASC Topic 712, Compensation-Nonretirement Postemployment Benefits (“ASC 712”). The recognition of restructuring costs requires the Company to make certain assumptions related to the amounts of employee severance benefits, the time period over which leased facilities will remain vacant and expected sublease terms and discount rates. Estimates and assumptions are based on the best information available at the time the obligation arises. These estimates are reviewed and revised as facts and circumstances dictate; changes in these estimates could have a material effect on the amount accrued in the consolidated balance sheet.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers. The standard provides companies with a single model for accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. The guidance permits companies to either apply the requirements retrospectively to all prior periods presented, or apply the requirements in the year of adoption, through a cumulative adjustment. In August 2015, the FASB issued ASU 2015-14, Deferral of the Effective date, which defers the required adoption date of ASU 2014-09 by one year. As a result of the deferred effective date, ASU 2014-09 will be effective for the Company in its first quarter of fiscal 2018. Early adoption is permitted but not before the original effective date of the new standard of the first quarter of fiscal 2017. The Company is in the process of evaluating the transition method that will be elected and the impact of adoption on its consolidated financial statements. In August 2014, the FASB issued ASU No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. The standard requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date the financial statements are issued and provides guidance on determining when and how to disclose going concern uncertainties in the financial statements. Certain disclosures will be required if conditions give rise to substantial doubt about an entity’s ability to continue as a going concern. ASU 2014-15 applies to all entities and is effective for annual and interim reporting periods ending after December 15, 2016, with early adoption permitted. The Company does not expect that the adoption of this standard will have a material effect on its financial statements. In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. The update changes the presentation of debt issuance costs to a direct deduction from the related debt liability rather than as an asset. Amortization of the costs will continue to be reported as interest expense. ASU 2015-03 is effective for annual and interim reporting periods ending after December 15, 2015. Early adoption is permitted, and the new guidance is to be applied on a retrospective basis to all prior periods. The Company does not expect that the adoption of this standard will have a material effect on its financial statements. In July 2015, the FASB issued ASU No. 2015-11, Simplifying the Measurement of Inventory. The new guidance was issued to more closely align the measurement of inventory in U.S. GAAP with the measurement of inventory in International Financial Reporting Standards. The core principle of this updated guidance is that an entity should measure inventory at the lower of cost or net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The amendments in ASU 2015-11 apply to inventory that is measured using the first-in, first-out or average cost methods. ASU 2015-11 is effective for annual and interim reporting periods ending after December 15, 2016, including interim periods within those fiscal years and should be applied prospectively. Early adoption is permitted as of the beginning of an interim or annual reporting period. The Company does not expect that the adoption of this standard will have a material effect on its financial statements.
Fair Value Measurements and Disclosures	The Company records certain financial instruments at fair value in accordance with the Fair Value Measurements and Disclosures Topic of the FASB ASC. As of September 30, 2015, the financial instruments to which this topic applied were foreign currency forward contracts. As of September 30, 2015, the fair value of these foreign currency forward contracts was a liability of $46,000 which is recorded in “accounts payable and accrued liabilities" in the consolidated balance sheet. The fair value of these derivative instruments is measured using models following quoted market prices in active markets for identical instruments, which is a Level 2 input under the fair value hierarchy of the Fair Value Measurements and Disclosures Topic of the FASB ASC.
Derivatives and Hedging	Maxwell uses forward contracts to hedge certain monetary assets and liabilities, primarily receivables, payables and cash balances, denominated in foreign currencies. The change in fair value of these forward contracts represents a natural hedge as gains and losses on these instruments partially offset the changes in the fair value of the underlying monetary assets and liabilities due to movements in currency exchange rates. These forward contracts generally expire in one month. These contracts are considered economic hedges but are not designated as hedges under the Derivatives and Hedging Topic of the FASB ASC, therefore, the change in the fair value of the instrument is recognized each period in the consolidated statement of operations.