Nature of Operations	12 Months Ended
Nature of Operations	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	NATURE OF OPERATIONS Energy Focus, Inc. engages primarily in the design, development, manufacturing, marketing and sale of energy-efficient lighting systems and controls and recently announced development of ultraviolet light disinfection (“UVCD”) products. We develop, market and sell high quality light-emitting diode (“LED”) lighting products and UVCD products and controls in the commercial and military maritime markets (“MMM”). Our mission is to enable our customers to run their facilities and offices with greater energy efficiency, productivity, and human health through advanced LED retrofit and UVCD solutions. Our goal is to be the LED and human-centric lighting (“HCL”) technology and market leader for the most demanding applications where performance, quality, value (high quality at an affordable price), environmental impact and health are considered paramount. We specialize in LED lighting retrofit by replacing fluorescent, high-intensity discharge lighting and other types of lamps in institutional buildings for primarily indoor lighting applications with our innovative, high-quality commercial and military tubular LED (“TLED”), as well as other LED and lighting control products. On October 14, 2020, we also announced the launch of our UVCD product portfolio. The LED lighting industry has changed dramatically over the past several years due to increasing commoditization, competition and price erosion. We have been experiencing these industry forces in both our military business since 2016 and in our commercial segment, where we once commanded significant price premiums for our flicker-free TLEDs with primarily 10-year warranties. Since April 2019, we have focused on redesigning our products for lower costs and consolidating our supply chain for stronger purchasing power where appropriate in order to price our products more competitively. Despite these efforts, the pricing of our legacy products remains at a premium to the competitive range and we expect aggressive pricing actions and commoditization to continue to be a headwind until our more differentiated new products ramp in volume. These trends are not unique to Energy Focus as evidenced by the increasing number of industry peers facing challenges, exiting LED lighting, selling assets and even going out of business. In addition to continuous, scheduled cost reductions, our strategy to combat these trends is to move up the value chain, with more innovative and differentiated products and solutions that offer greater, distinct value to our customers. Two specific examples of these products we have recently developed include the RedCap®, our emergency backup battery integrated TLED, and EnFocus™, our new dimmable/tunable lighting and control platform that we launched in 2020. We believe our revamped go-to-market strategy that focuses more on direct-sales and additional sales representatives and listens to the voice of the customer has led to better and more impactful product development efforts and will eventually translate into larger addressable market and greater sales growth for us. During 2020, we continued to see the benefits from the relaunch efforts (described below) undertaken by the new, current management team, in addition to a number of strategic sourcing projects completed during 2020. It is our belief that the continued momentum of the efforts undertaken in 2019 and into 2020, along with the development and launch of new and innovative products, will over time result in improved sales and bottom-line performance for the Company. We launched our EnFocus™ platform during the second quarter of 2020 and continued to receive positive feedback from existing, new, and prospective customers. The EnFocus™ platform offers two immediately available product lines: EnFocus™ DM, which provides a dimmable lighting solution, and EnFocus™ DCT, which provides both a dimmable and color tunable lighting solution. EnFocus™ enables buildings to have dimmable, color tunable and circadian-ready lighting using existing wiring, without requiring any wireless communications, through a relatively simple upgrade with EnFocus™ switches and tubular LEDs, a more environmentally sustainable solution compared with replacing each lighting fixture. In addition, in response to the COVID-19 pandemic and an anticipated increase in sanitation and hygiene demand for buildings, facilities and homes, we started developing advanced UVCD products for both consumer as well as the commercial and industrial markets in the first quarter of 2020. We announced the following three UVCD products in October 2020: abUV™ circadian lighting and UVCD air disinfection integrated troffers controlled by the EnFocus™ platform technology; the nUVo™ portable disinfection device for offices and homes; and the mUVe™ autonomous robot designed for surface disinfection. Since April 2019, we experienced significant change at the Company. Prior to James Tu returning as Chief Executive Officer and Chairman at the beginning of April 2019, the Company had experienced significant sales declines, operating losses and increases in its inventory. Immediately upon Mr. Tu returning to the Company, significant additional restructuring efforts were undertaken. The Company has since then replaced the entire senior management team, significantly reduced non-critical expenses, minimized the amount of inventory the Company was purchasing, dramatically changed the composition of our board of directors, as well as adding very selectively to the executive team by hiring Tod Nestor as President and Chief Financial Officer at the beginning of July 2019 and James R. Warren as Senior Vice President, General Counsel and Corporate Secretary in September 2020, in addition to recruiting new departmental leaders across the Company. The cost savings efforts undertaken included the Company implementing phased actions to reduce costs to minimize cash usage. Our initial actions included the elimination of certain positions, restructuring of the sales organization and incentive plan, flattening of the senior management team, additional operational streamlining, management compensation reductions, and outsourcing of certain functions including certain elements of supply chain and marketing. On June 11, 2020, in accordance with previous stockholder approval, our Board of Directors effected a 1-for-5 (the “Split Ratio”) reverse stock split of the Company’s common stock, par value $0.0001 per share. The reverse stock split became effective immediately upon the filing of the Certificate of Amendment to the Company’s Certificate of Incorporation, as amended (the “Certificate of Incorporation”), with the Delaware Secretary of State (the “Effective Time”). At the Effective Time, every five shares of common stock issued and outstanding automatically combined into one validly issued, fully paid and non-assessable share of common stock. No fractional shares were issued as a result of the reverse stock split. The $0.0001 par value per share of common stock and other terms of the common stock were not affected by the reverse stock split. The number of authorized shares of common stock under the Certificate of Incorporation remained unchanged at 50,000,000 shares. Proportional adjustments were made to the conversion and exercise prices of our outstanding warrants and stock options, and to the number of shares issued and issuable under our stock incentive plans in connection with the reverse stock split. The information presented in the financial statements for all prior periods have been retroactively adjusted to reflect the reverse stock split. Preferred shares outstanding were not affected by the reverse stock split and, as such, those shares have not been adjusted.