Organization And Summary Of Significant Accounting Policies	3 Months Ended
	Mar. 29, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization And Summary Of Significant Accounting Policies	ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Organization SunPower Corporation (together with its subsidiaries, "SunPower," "we," "us," and "our") is a leading global energy company that delivers complete solar solutions to residential and commercial customers worldwide through an array of hardware, software, and financing options and through solar power solutions, operations and maintenance ("O&M") services, and "Smart Energy" solutions. SunPower's Smart Energy initiative is designed to add layers of intelligent controls to homes, buildings and grids - all personalized through easy-to-use customer interfaces. Of all the solar cells commercially available to the mass market, we believe our solar cells have the highest solar power conversion efficiency, a measurement of the amount of sunlight converted by the solar cell into electricity. SunPower is a majority-owned subsidiary of Total Solar INTL SAS ("Total", formerly Total Energies Nouvelles Activités USA) and Total Gaz Electricité Holdings France SAS (“Total Gaz”), each a subsidiary of Total S.A. ("Total S.A.") (see "Note 2. Transactions with Total and Total S.A"). Liquidity The global spread of the coronavirus ("COVID-19") has created significant uncertainty and economic disruptions worldwide. In our response to the COVID-19 pandemic, we have instituted certain measures, including requirements to work remotely for the majority of our workforce, travel restrictions and the idling of our factories in France, Malaysia, Mexico, the Philippines, and the U.S consistent with actions taken or recommended by governmental authorities. In addition, we have implemented several mitigating actions to prudently manage our business during the current industry uncertainty relating to the COVID-19 pandemic. These actions include reducing management salaries, freezing all hiring and merit increases, reducing capital expenditures and discretionary spending, and temporarily moving most of our employees to a four-day work week in recognition of reduced demand and workloads due to the pandemic. We also continue to focus on improving our overall operating performance and liquidity, including managing cash flow and working capital. Despite the challenging and volatile economic conditions, we believe that our total cash and cash equivalents will be sufficient to meet our obligations over the next 12 months from the date of issuance of our financial statements. While we have not drawn on it, we have the ability to enhance our available cash by borrowing up to $55.0 million under our Green Revolving Credit Agreement ("2019 Revolver"). See Note 10. Debt and Credit Sources. In addition, we have historically been successful in our ability to divest certain investments and non-core assets, secure other sources of financing, such as accessing the capital market, and implement other cost reduction initiatives such as restructuring, to satisfy our liquidity needs; however, our access to these sources could be materially and adversely impacted and we may not be able to receive terms as favorable as we would ordinarily expect to receive. Although we have historically been able to generate liquidity, we cannot predict, with certainty, the outcome of our actions to generate liquidity as planned. Additionally, we are uncertain of the full extent to which the COVID-19 pandemic will impact our business, operations and financial results over time. Basis of Presentation and Preparation Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of SunPower and our wholly-owned subsidiaries, and have been prepared by us in accordance with generally accepted accounting principles in the United States ("United States" or "U.S.," and such accounting principles, "U.S. GAAP") for interim financial information, and include the accounts of SunPower, all of our subsidiaries and special purpose entities, as appropriate under U.S. GAAP. All intercompany transactions and balances have been eliminated on consolidation. The financial information included herein is unaudited, and reflects all adjustments which are, in the opinion of our management, of a normal recurring nature and necessary for a fair statement of the results for the periods presented. The December 29, 2019 consolidated balance sheet data was derived from SunPower’s audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended December 29, 2019, as filed with the Securities and Exchange Commission ("SEC") on February 18, 2020 but does not include all disclosures required by U.S. GAAP. The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in SunPower's Annual Report on Form 10-K for the fiscal year ended December 29, 2019. The operating results for the three months ended March 29, 2020 are not necessarily indicative of the results that may be expected for fiscal year 2020, or for any other future period. We have a 52-to-53-week fiscal year that ends on the Sunday closest to December 31. Accordingly, every fifth or sixth year will be a 53-week fiscal year. The current fiscal year, fiscal 2020, is a 53-week fiscal year, while fiscal year 2019 was a 52-week fiscal year. The first quarter of fiscal 2020 ended on March 29, 2020, while the first quarter of fiscal 2019 ended on March 31, 2019. Management Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires our management to make estimates and assumptions that affect the amounts reported in these condensed consolidated financial statements and accompanying notes. Significant estimates in these condensed consolidated financial statements include revenue recognition, specifically the nature and timing of satisfaction of performance obligations, standalone selling price of performance obligations and variable consideration; allowances for credit losses, including estimating macroeconomic factors affecting historical recovery rate of receivables; inventory and project asset write-downs; stock-based compensation; fair value assumptions for solar power systems and other long-lived assets sold under sale-leaseback transactions; long-lived asset impairment, specifically estimates for valuation assumptions including discount rates and future cash flows; economic useful lives of property, plant and equipment, and intangible assets; fair value of investments, including equity investments for which we apply the fair value option and other financial instruments; residual value of solar power systems; valuation of contingencies such as accrued warranty; the incremental borrowing rate used in discounting of lease liabilities; the fair value of indemnities provided to customers and other parties; and income taxes and tax valuation allowances. As a result of the uncertainty involved with industry impacts of COVID-19, many of our estimates and assumptions require increased judgment and carry a higher degree of variability and volatility. These estimates may change as impacts become more certain and additional information becomes available, which may result in a significant change to our estimates in future periods. Actual results could materially differ from those estimates. Summary of Selected Significant Accounting Policies Included below, are selected significant accounting policies that were added or modified during the three months ended March 29, 2020 as a result of new transactions entered into or the adoption of new accounting policies. Refer to our Annual Report on Form 10-K for the fiscal year ended December 29, 2019 for the full list of our significant accounting policies. Financial Instruments - Credit Losses Effective December 30, 2019, we adopted Accounting Standards Update ("ASU") No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13) and subsequent amendment to the initial guidance: ASU 2018-19, ASU 2019-04, ASU 2019-05, ASU 2019-10, ASU 2019-11, ASU 2020-02, and ASU 2020-03 (collectively, "Topic 326"). Topic 326 requires measurement and recognition of expected credit losses for financial assets held. The amendment applies to entities which hold financial assets and net investments in leases that are not accounted for at fair value through net income as well as loans, debt securities, accounts receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. For additional information on the changes resulting from the new standard and the impact to our financial results on adoption, refer to the section Recently Adopted Accounting Pronouncements below. We recognize an allowance for credit loss at the time a receivable is recorded based on our estimate of expected credit losses and adjust this estimate over the life of the receivable as needed. We evaluate the aggregation and risk characteristics of a receivable pool and develop loss rates that reflect historical collections, current forecasts of future economic conditions over the time horizon we are exposed to credit risk, and payment terms or conditions that may materially affect future forecasts. As of March 29, 2020, we reported $243.5 million of accounts receivable, net of allowances of $22.5 million. Based on aging analysis as of March 29, 2020, 83% of our trade accounts receivable was outstanding less than 60 days. Refer to Note 4. Balance Sheet Components for more details regarding changes in allowance for credit losses. We will continue to actively monitor the impact of the COVID-19 pandemic on expected credit losses. Recently Adopted Accounting Pronouncements In June 2016, the FASB issued Topic 326, to replace the prior incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. The amendments in Topic 326 apply to entities which hold financial assets and net investments in leases that are not accounted for at fair value through net income as well as loans, debt securities, accounts receivables, and any other financial assets not excluded from the scope that have the contractual right to receive cash. We adopted the ASU during the first quarter of fiscal 2020. The adoption did not have a material impact on our consolidated financial statements. In August 2018, the FASB issued ASU 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20) to add, remove, and clarify disclosure requirements related to defined benefit pension and other postretirement plans. We adopted the ASU during first quarter of fiscal 2020. The adoption did not have a material impact on our consolidated financial statements. In August 2018, the FASB issued ASU 2018-15, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40) requiring a customer in a cloud computing arrangement that is a service contract to follow the internal-use software guidance in ASC 350-40 to determine which implementation costs to capitalize as assets. We adopted the ASU during the first quarter of fiscal 2020. The adoption did not have a material impact on our consolidated financial statements. In October 2018, the FASB issued ASU 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities, which broadens the scope of the private company alternative to include all common control arrangements that meet specific criteria (not just leasing arrangements) and also eliminates the requirement that entities consider indirect interests held through related parties under common control in their entirety when assessing whether a decision-making fee is a variable interest. We adopted the ASU during the first quarter of fiscal 2020. The adoption did not have a material impact on our consolidated financial statements. In November 2018, the FASB issued ASU 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606, which 1) clarifies that certain transactions between collaborative arrangement participants should be accounted for as revenue under Topic 606; 2) adds unit-of-account guidance in Topic 808 to align with the guidance in Topic 606; and 3) requires that in a transaction with a collaborative arrangement participant that is not directly related to sales to third parties, presenting the transaction together with revenue recognized under Topic 606 is precluded if the collaborative arrangement participant is not a customer. We adopted the ASU during the first quarter of fiscal 2020. The adoption did not have a material impact on our consolidated financial statements. Recent Accounting Pronouncements Not Yet Adopted In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes, which simplifies the accounting for income taxes, eliminates certain exceptions within ASC 740, Income Taxes, and clarifies certain aspects of the current guidance to promote consistency among reporting entities. ASU 2019-12 is effective for us no later than the first quarter of fiscal 2021. Most amendments within the standard are required to be applied on a prospective basis, while certain amendments must be applied on a retrospective or modified retrospective basis. We are currently evaluating the impacts of the provisions of ASU 2019-12 on our financial statements and disclosures. In January 2020, the FASB issued ASU 2020-01, Investments—Equity Securities (Topic 321), Investments—Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815)—Clarifying the Interactions between Topic 321, Topic 323, and Topic 815. The amendment clarifies accounting for equity investments and non-derivative forward contracts or purchased call options under ASC 321. ASU 2020-01 is effective no later than the first quarter of fiscal 2021. Early adoption is permitted, and the ASU should be applied prospectively. While we are still evaluating the impacts of the provisions of ASU 2020-01 on our financial statements and disclosures, the impact is not expected to be material.