Description of Business and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2014
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 accounting principles generally accepted in the United States (“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.
Reclassification, Policy	Reclassifications Certain prior period amounts in the consolidated statement of cash flows for the six months ended June 30, 2013 have been reclassified to conform to the current period presentation. These reclassifications do not impact reported net income (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 Tax Disclosure	Valuation Allowance on Deferred Tax Asset At June 30, 2014, the Company has a cumulative valuation allowance recorded offsetting its worldwide net deferred tax assets of $59.5 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 evaluates positive and negative evidence in connection with its assessment of the recoverability of the deferred tax assets. The key objective negative evidence, which is generally difficult to overcome, is a cumulative loss over the past three years. Based on financial projections through 2018, the cumulative three-year position may shift from a loss to an income position as soon as 2018. While other factors will need to be considered during the Company’s assessment of the U.S. valuation allowance, three-years cumulative income is considered significant positive evidence to support realization of all or a portion of the net deferred tax assets. However, the Company will also need to consider whether it expects to be in a cumulative loss position in the near future. Based on the Company’s current financial projections, the Company may begin releasing the U.S. valuation allowance as soon as 2018.
Cash and Cash Equivalents, Restricted Cash
Warranty Obligation	Warranty Obligation The Company provides warranties on all product sales. The majority of the Company’s warranties are for one to four years in the normal course of business. 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. Beginning in the fourth quarter of 2011, for three distributors of the Company's products, the Company offered extended payment terms which allowed these distributors to pay the Company after they received payment from their customer, with respect to certain sales transactions. Also beginning in the fourth quarter of 2011, for one other distributor of the Company's products, the Company offered return rights and profit margin protection with respect to certain sales transactions. Therefore, for these four distributors, the Company determined that the revenue recognition criteria of SAB 101 and 104 were not met at the time of shipment, as there was no fixed or determinable price, nor was collection reasonably assured, at least with respect to certain sales transactions. As a result, for the three distributors provided with extended payment terms, which did not provide for a fixed or determinable price, the Company deferred the recognition of revenue on all sales beginning in the fourth quarter of 2011 to the period in which cash is received. For the one distributor provided with return rights and profit margin protection, for which the Company could not estimate exposure, the Company deferred the recognition of revenue on all sales beginning in the fourth quarter of 2011 until the distributor confirmed to the Company that it was not entitled to any further returns or credits. During the third quarter of 2013, this distributor confirmed to the Company that it was not entitled to any further returns or credits, therefore, previously unrecognized revenue related to this distributor was recognized in the quarter ended September 30, 2013. Although the Company had deferred revenue recognition for a significant amount of sales to these four distributors through the quarter ended September 30, 2013, subsequent to this date the amount of deferred revenue related to these distributors has been insignificant. In addition to the deferred revenue arrangements discussed in the preceding paragraph, 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. As of June 30, 2014 and December 31, 2013, cumulative sales totaling $2.6 million and $4.5 million, respectively, had not yet been recognized as revenue. The Company has recorded the cost basis of inventory shipped to customers prior to the achievement of the revenue recognition criteria of approximately $1.6 million and $2.5 million at June 30, 2014 and December 31, 2013, respectively, in "inventory" in the consolidated balance sheets. 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 June 30, 2014 and December 31, 2013 of $3.2 million and $1.0 million, respectively, 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.
Net Income (Loss) per Share	Net Income (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.
Derivatives and Hedging	Maxwell uses forward contracts to hedge certain monetary assets and liabilities, primarily receivables and payables, 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.
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 June 30, 2014, the financial instruments to which this topic applied were foreign currency forward contracts. As of June 30, 2014, the fair value of these foreign currency forward contracts was an asset of $66,000 which is recorded in “prepaid expenses and other current assets" 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.