Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2013
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. All significant 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	Reclassifications Certain prior period amounts in the consolidated statements of operations 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.
Cash and Cash Equivalents, Restricted Cash	Restricted Cash As of September 30, 2013, the Company had restricted cash of $4.1 million. Restricted cash of $2.3 million relates to a stand-by letter of credit that provides financial assurance the Company will fulfill certain contractual obligations. Restricted cash of $1.8 million represents a compensating balance on deposit with the bank as collateral for outstanding borrowings with the bank. The cash balances are restricted to withdrawal and classified as current assets on the balance sheet because the restrictions are expected to be released not later than one year from the balance sheet date of September 30, 2013.
Warranty Obligation	Warranty Obligation The Company provides warranties on all product sales. The majority of the Company’s warranties are for one to two 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 determined to defer 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 determined to defer the recognition of revenue on all sales beginning in the fourth quarter of 2011 until the distributor confirmed with the Company that they were not entitled to any further returns or credits. During third quarter of 2013, this distributor confirmed with the Company that they were not entitled to any further returns or credits, therefore, previously deferred revenue related to this distributor was recognized in the quarter ended September 30, 2013. Related to these arrangements, as well as other less significant arrangements requiring the deferral of revenue, for the three and nine months ended September 30, 2013, the Company deferred revenue recognition on net sales of $3.9 million and $13.4 million, respectively, and recognized previously deferred revenue of $15.2 million and $24.9 million, respectively. For the three and nine months ended September 30, 2012, the Company deferred revenue recognition on net sales of $4.0 million and $16.9 million, respectively, and recognized previously deferred revenue of $1.2 million and $6.6 million, respectively. The Company has recorded the cost basis of inventory shipped to customers for which revenue has been deferred of approximately $3.2 million and $9.2 million at September 30, 2013 and December 31, 2012 , respectively, in "inventory" in the condensed consolidated balance sheets.
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 a foreign currency. The change in fair value of these instruments represents a natural hedge as gains and losses offset the changes in the underlying fair value of the monetary assets and liabilities due to movements in currency exchange rates. These contracts generally expire in one month. These contracts are considered economic hedges and 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 currently 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 September 30, 2013, the financial instruments to which this topic applied were foreign currency forward contracts. As of September 30, 2013, the fair value of these foreign currency forward contracts was a liability of $977,000 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.