Basis of Presentation (Policies)	9 Months Ended
Basis of Presentation (Policies)	Sep. 30, 2014
Basis of Presentation
Principles of Consolidation	*Principles of Consolidation:* The accompanying unaudited condensed interim consolidated financial statements include the financial statements of the Company and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. It is the Company’s policy to reclassify prior period consolidated financial statements to conform to current period presentation.
Interim Financial Statments	*Interim Financial Statements*: The accompanying unaudited condensed interim consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). In the opinion of management, all adjustments, which consist solely of normal recurring adjustments, necessary to present fairly, in accordance with U.S. generally accepted accounting principles (GAAP), the financial position, results of operations and cash flows for all periods presented, have been made. The results of operations for the interim periods presented are not necessarily indicative of the results that may be expected for the full year. Certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles have been condensed or omitted. These unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K, as amended by the Company’s Annual Report on Form 10-K/A, filed for the fiscal year ended December 31, 2013. The information presented in the accompanying condensed consolidated balance sheet as of December 31, 2013 has been derived from the Company’s December 31, 2013 audited consolidated financial statements. All other information has been derived from the Company’s unaudited condensed consolidated financial statements as of September 30, 2014 and for the three and nine months ended September 30, 2014 and 2013.
Use of Management Estimates	*Use of Management Estimates:* The unaudited condensed interim consolidated financial statements have been prepared in conformity with GAAP, which require management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Revenue Recognition	*Revenue Recognition* The Company recognizes revenue under arrangements for products and services, which may include the sale of products (GenDrive units) and related services, including revenue from installation, service and maintenance, spare parts, hydrogen fueling services, which may include hydrogen supply as well as hydrogen fueling infrastructure, and leased units. The Company also recognizes revenue under research and development contracts, which are primarily cost reimbursement contracts associated with the development of PEM fuel cell technology. The Company enters into revenue arrangements that may contain a combination of fuel cell systems and equipment, which may be sold, or under a limited number of arrangements leased to customers, installation, service, maintenance, spare parts, hydrogen fueling and other support services. For these multiple deliverable arrangements, the Company accounts for each separate deliverable as a separate unit of accounting if the delivered item or items have value to the customer on a standalone basis. The Company considers a deliverable to have standalone value if the item is sold separately by us or another entity or if the item could be resold by the customer. The Company allocates revenue to each separate deliverable based on its relative selling price. For a majority of our deliverables, the Company determines relative selling prices using its best estimate of the selling price as vendor-specific objective evidence and third-party evidence is generally not available for the deliverables involved in its revenue arrangements due to a lack of a competitive environment in selling fuel cell technology. When determining estimated selling prices, the Company may consider the cost to produce the deliverable, the anticipated margin on that deliverable, the selling price and profit margin for similar parts, the Company’s ongoing pricing strategy and policies, the value of any enhancements that have been built into the deliverable and the characteristics of the varying markets in which the deliverable is sold, as applicable. The Company determines estimated selling prices for deliverables in its agreements based on the specific facts and circumstances of each arrangement and analyzes the estimated selling prices used for its allocation of arrangement consideration at least annually. Selling prices will be analyzed on a more frequent basis if a significant change in the Company’s business necessitates a more timely analysis or if the Company experiences significant variances in its selling prices. Once relative selling prices are determined, the Company proportionately allocates the sale consideration to each element of the arrangement. The allocated sales consideration related to fuel cell systems and equipment, spare parts, and hydrogen is recognized as revenue at shipment if title and risk of loss have passed to the customer, there is persuasive evidence of an arrangement, the sales price is fixed or determinable, collection of the related receivable is reasonably assured, and customer acceptance criteria, if any, have been successfully demonstrated. The allocated sales consideration related to installation, service, maintenance, and hydrogen delivery infrastructure is generally recognized as revenue when completed or on a straight-line basis over the term of the contract, as appropriate. In the case of consignment sales, the Company does not begin recognizing revenue until the customer has accepted the product, at which time the risks and rewards of ownership have transferred, the price is fixed, and the Company has a reasonable expectation of collection upon billing. The Company does not include a right of return on its products other than rights related to warranty provisions that permit repair or replacement of defective goods. The Company accrues for anticipated warranty costs at the same time that revenue is recognized for the related product. The Company has also sold extended warranty contracts that generally provide for a five to ten year warranty from the date of product installation. These types of contacts are accounted for as a separate deliverable, and accordingly, revenue generated from these transactions is deferred and recognized in income over the warranty period, generally on a straight-line basis. Additionally, the Company may enter into annual service and maintenance contracts that are billed monthly. Revenue generated from these transactions is recognized in income on a straight-line basis over the term of the contract. At September 30, 2014 and December 31, 2013, the Company had unbilled amounts from product and service revenues in the amount of approximately $1,821,000 and $184,000, respectively, which is included in other current assets in the accompanying condensed consolidated balance sheets. At September 30, 2014 and December 31, 2013, the Company had deferred product and service revenues in the amount of $10.7 million and $9.0 million, respectively.
Common Stock Warrant Accounting	*Common Stock Warrant Accounting* The Company accounts for common stock warrants in accordance with applicable accounting guidance provided in Accounting Standards Codification (ASC) Subtopic 815-40, Derivatives and Hedging — Contracts in Entity’s Own Equity, as either derivative liabilities or as equity instruments depending on the specific terms of the warrant agreement. In compliance with applicable securities law, registered common stock warrants that require the issuance of registered shares upon exercise and do not sufficiently preclude an implied right to cash settlement are accounted for as derivative liabilities. We classify these derivative warrant liabilities on the accompanying consolidated balance sheets as a long-term liability, which is revalued at each balance sheet date subsequent to the initial issuance using the Black-Scholes pricing model. The Black-Scholes pricing model, which is based, in part, upon unobservable inputs for which there is little or no market data, requires the Company to develop its own assumptions. Changes in the fair value of the warrants are reflected in the accompanying consolidated statements of operations as change in fair value of common stock warrant liability.
Joint Venture	*Joint Venture* The Company accounts for investments in joint ventures in which we have significant influence in accordance with applicable accounting guidance in ASC Subtopic 323-10, Investments — Equity Method and Joint Ventures — Overall. On February 29, 2012 we completed the formation of our joint venture with Axane, S.A., a subsidiary of Air Liquide, under the name HyPulsion, S.A.S. (HyPulsion or the JV). The principal purpose of the JV is to develop and sell hydrogen fuel cell systems for the European material handling market. Axane contributed cash at the closing and has made additional fixed cash contributions in 2013 and 2014 in exchange for an initial 55% ownership of the JV, subject to certain conditions. We have not contributed any cash to the JV and we are not obligated to contribute any cash. We contributed to the JV the right to use our technology, including design and technology know-how on GenDrive systems, in exchange for an initial 45% ownership of the JV. On April 19, 2013 Axane purchased an additional 25% ownership interest in HyPulsion from the Company for a cash purchase price of $3.3 million (Euro 2.5 million). We now own 20% and Axane owns 80% of HyPulsion, and we will share in 20% of the profits and losses from the JV. The Company has the right to purchase an additional 60% of HyPulsion from Axane at any time between January 4, 2018 and January 29, 2018 at a formula price. If the Company exercises its purchase right, Axane will have the right, at any time between February 1, 2018 and December 31, 2021, to require the Company to buy the remaining 20% interest at a formula price. The Company and the JV have also entered into an engineering service agreement under which, among other things, the Company provides the JV with engineering and technical services. The JV made payments to the Company of $1,622,576 and $8,978,747 for the nine months ended September 30, 2014 and September 30, 2013, respectively, for engineering and technical services, as well as for the purchase of fuel cell systems and parts. In accordance with the equity method of accounting, the Company will increase its investment in the JV by its share of any earnings, and decrease its investment in the JV by its share of any losses. Losses in excess of the investment must be restored from future profits before we can recognize our proportionate share of profits. As of September 30, 2014, the Company had a zero basis for its investment in the JV.
Recent Accounting Pronouncements	*Recent Accounting Pronouncements* On May 28, 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. The new standard is effective for the Company on January 1, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting. In August 2014, the FASB issued ASU No. 2014-09, Disclosures of Uncertainties about an Entity’s Ability to Continue as a Going Concern, which requires the Company to assess their ability to continue as a going concern by incorporating and expanding upon certain principles that are currently in U.S. auditing standards. Specifically, the amendments (1) provide a definition of the term substantial doubt, (2) require an evaluation every reporting period including interim periods, (3) provide principles for considering the mitigating effect of Company’s plans, (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans, (5) require an express statement and other disclosures when substantial doubt is not alleviated, and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). The new standard is effective for reporting periods beginning after December 15, 2006. Early application is permitted. The Company does not expect the adoption of this update to have a significant effect on our financial statements.
Cash Equivalents	*Cash Equivalents* Cash equivalents consist of money market accounts with an initial term of less than three months. For purposes of the consolidated statements of cash flows, the Company considers all highly-liquid debt instruments with original maturities of three months or less to be cash equivalents. The Company’s cash and cash equivalents are deposited with financial institutions located in the U.S. and may at times exceed insured limits.

Disclosure of accounting policy for cash and cash equivalents, including the policy for determining which items are treated as cash equivalents. Other information that may be disclosed includes (1) the nature of any restrictions on the entity's use of its cash and cash equivalents, (2) whether the entity's cash and cash equivalents are insured or expose the entity to credit risk, (3) the classification of any negative balance accounts (overdrafts), and (4) the carrying basis of cash equivalents (for example, at cost) and whether the carrying amount of cash equivalents approximates fair value.

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Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.

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Disclosure of accounting policy for the equity method of accounting for investments in common stock or other interests including unconsolidated subsidiaries, corporate joint ventures, noncontrolling interests in real estate ventures, limited partnerships, and limited liability companies. The accounting policy may include information such as: (1) initially recording an investment in the stock of an investee at cost; (2) adjusting the carrying amount of the investment to recognize the investor's share of the earnings or losses of the investee after the date of acquisition; and (3) adjustments to reflect the investor's share of changes in the investee's capital (dividends). This disclosure may also include a detailed description of the policy for determining the amount of equity method losses recognized after an investment has been reduced to zero as a result of previous losses, reasons for not using the equity method when the investor company owns 20 percent or more of the voting stock of the investee's company (including identification of the significant investee), reasons for using the equity method when the ownership percentage is less than 20 percent, and discussion of recognition of equity method losses when an investor's total investment in an investee includes, in addition to an investment in common stock, other investments such as preferred stock and loans to the investee. An entity also may describe how such investments are assessed for impairment.

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Disclosure of accounting policy for revenue recognition. If the entity has different policies for different types of revenue transactions, the policy for each material type of transaction is generally disclosed. If a sales transaction has multiple element arrangements (for example, delivery of multiple products, services or the rights to use assets) the disclosure may indicate the accounting policy for each unit of accounting as well as how units of accounting are determined and valued. The disclosure may encompass important judgment as to appropriateness of principles related to recognition of revenue. The disclosure also may indicate the entity's treatment of any unearned or deferred revenue that arises from the transaction.

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