Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation We have prepared the condensed consolidated financial statements included herein pursuant to the rules and regulations of the U.S. Securities and Exchange Commission ("SEC"), and as permitted by those rules, including all disclosures required by generally accepted accounting principles as applied in the United States (“U.S. GAAP”). All intercompany transactions and balances have been eliminated upon consolidation. Certain prior period amounts have been reclassified to conform to the current period presentation. As disclosed in the 2020 Annual Report on Form 10-K, effective on December 31, 2020, we lost our emerging growth company ("EGC") status which accelerated the adoption of ASC 842 - Leases. As a result, we adjusted our previously reported consolidated financial statements effective January 1, 2020.
Principles of Consolidation	Principles of Consolidation These condensed consolidated financial statements reflect our accounts and operations and those of our subsidiaries in which we have a controlling financial interest. We use a qualitative approach in assessing the consolidation requirement for each of our variable interest entities ("VIEs"), which we refer to as a tax equity partnership (each such VIE, also referred to as our power purchase agreement entities ("PPA Entities")). This approach focuses on determining whether we have the power to direct those activities of the PPA Entities that most significantly affect their economic performance and whether we have the obligation to absorb losses, or the right to receive benefits, that could potentially be significant to the PPA Entities. For all periods presented, we have determined that we are the primary beneficiary in all of our operational PPA Entities, as discussed in Note 11 - Portfolio Financings. We evaluate our relationships with the PPA Entities on an ongoing basis to ensure that we continue to be the primary beneficiary. All intercompany transactions and balances have been eliminated upon consolidation.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and the accompanying notes. The most significant estimates include the determination of the stand-alone selling price, including material rights estimates, inventory valuation, specifically excess and obsolescence provisions for obsolete or unsellable inventory and, in relation to property, plant and equipment (specifically Energy Servers), assumptions relating to economic useful lives and impairment assessments. Other accounting estimates include variable consideration relating to product performance guaranties, lease and non-lease components and related financing obligations such as incremental borrowing rates, estimated output, efficiency and residual value of the Energy Servers, product performance warranties and guaranties and extended maintenance, derivative valuations, estimates for recapture of the U.S. investment tax credit ("ITC") and similar federal tax benefits, estimates relating to contractual indemnities provisions, estimates for income taxes and deferred tax asset valuation allowances, and stock-based compensation costs. The full extent to which the COVID-19 pandemic will directly or indirectly impact our business, results of operations and financial condition, including sales, expenses, our allowance for doubtful accounts, stock-based compensation, the carrying value of our long-lived assets, inventory, financial assets, and valuation allowances for tax assets, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning the COVID-19 pandemic and the actions taken to contain it or treat it, as well as the economic impact on local, regional, national and international customers, suppliers and markets. We have made estimates of the impact of COVID-19 within our condensed consolidated financial statements and there may be changes to those estimates in future periods as new information becomes available. Actual results could differ materially from these estimates under different assumptions and conditions.
Foreign Currency Transactions	Foreign Currency Transactions The functional currencies of most of our foreign subsidiaries are the U.S. dollar since the subsidiaries are considered financially and operationally integrated with their domestic parent. For these subsidiaries, the foreign currency monetary assets and liabilities are remeasured into U.S. dollars at end-of-period exchange rates. Any currency transaction gains and losses are included as a component of other expense in our condensed consolidated statements of operations. The functional currency of our joint venture in the Republic of Korea is the local currency, the South Korean won ("KRW"), since the joint venture is financially independent of its U.S. parent and the KRW is the currency in which the joint venture generates and expends cash. Assets and liabilities of this entity are translated at the rate of exchange at the balance sheet date. Revenues and expenses are translated at the weighted average rate of exchange during the period. For this entity, translation adjustments resulting from the process of translating the KRW financial statements into U.S dollars are included in other comprehensive loss. Translation adjustments attributable to noncontrolling interests are allocated to and reported as part of the noncontrolling interests in the condensed consolidated financial statements.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Other than the adoption of the accounting guidance mentioned below, there have been no other significant changes in our reported financial position or results of operations and cash flows resulting from the adoption of new accounting pronouncements. Accounting Guidance Implemented in 2021 In August 2020, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) ("ASU 2020-06"). The new standard simplifies the accounting for convertible instruments by eliminating the conversion option separation model for convertible debt that can be settled in cash and by eliminating the measurement model for beneficial conversion features. The guidance is effective for fiscal years beginning after December 15, 2021, with early adoption permitted as early as fiscal years (including interim periods) beginning after December 15, 2020. Consequently, a convertible debt instrument will be accounted for as a single liability measured at its amortized cost, as long as no other features require bifurcation and recognition as derivatives. There will no longer be a debt discount representing the difference between the carrying value, excluding issuance costs, and the principal of the convertible debt instrument and, as a result, there will no longer be interest expense from the amortization of the debt discount over the term of the convertible debt instrument. The amendments in this update also require the if-converted method to be applied for all convertible instruments when calculating diluted earnings per share. We elected to early adopt ASU 2020-06 as of January 1, 2021 using the modified retrospective transition method, which resulted in a cumulative-effect adjustment to the opening balance of accumulated deficit on the date of adoption. Prior period condensed consolidated financial statements were not restated upon adoption. Upon adoption of ASU 2020-06, the Company combined the previously separated equity component with the liability component of our 2.5% Green Convertible Senior Notes due August 2025. These components are now together classified as Recourse debt, thereby eliminating the subsequent amortization of the debt discount as interest expense. Similarly, the portion of issuance costs previously allocated to equity was reclassified to debt and will be amortized as interest expense. Accordingly, we recorded a decrease to Accumulated deficit of $5.3 million, a decrease to Additional paid-in capital of $126.8 million, and an increase to Recourse debt, non-current of approximately $121.5 million. There is no deferred tax impact related to the adoption of ASU 2020-06 due to our full valuation allowance. Accounting Guidance Not Yet Adopted Cessation of LIBOR - In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848) Facilitation of the Effects of Reference Rate Reform on Financial Reporting ("ASU 2020-04"), which provides optional expedients for a limited period of time for accounting for contracts, hedging relationships, and other transactions affected by the London Interbank Offered Rate ("LIBOR") or other reference rate expected to be discontinued. ASU 2020-04 is effective immediately and may be applied prospectively to contract modifications made and hedging relationships entered into or evaluated on or before December 31, 2022. We are currently evaluating the impact of the adoption of ASU 2020-04 on our consolidated financial statements.