Organization and Description of Business	6 Months Ended	12 Months Ended
Jun. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Organization and Description of Business	Note 1. Organization and Description of Business Description of Business: XL Fleet Corp. and its subsidiaries (“XL Fleet” or the “Company”) is a leading provider of fleet electrification solutions for commercial vehicles in North America, offering solutions for vehicle electrification (“Drive Systems”) and infrastructure solutions such as vehicle charging stations through its XL Grid programs, as further described below. XL Fleet has over 4,400 electrified powertrain systems sold and driven over 160 million miles by over 235 fleets, as of June 30, 2021. XL Fleet’s vision is to become the world leader in commercial fleet electrification solutions, with a mission of accelerating the adoption of fleet electrification systems through cost effective, customer tailored and comprehensive solutions. Merger and Reorganization: On December 21, 2020, privately held XL Hybrids, Inc., a Delaware corporation, (“Legacy XL”) consummated the merger pursuant to that certain Agreement and Plan of Reorganization, dated as of September 17, 2020 (the “Merger Agreement”), by and among Pivotal Investment Corporation II (“Pivotal”), PIC II Merger Sub Corp., a Delaware corporation and wholly owned subsidiary of Pivotal (“Merger Sub”), and Legacy XL. Pursuant to the terms of the Merger Agreement, a business combination between Legacy XL and Pivotal was effected through the merger of Merger Sub with and into Legacy XL, with Legacy XL surviving as a wholly-owned subsidiary of Pivotal (the “Merger” and, collectively with the other transactions described in the Merger Agreement, the “Business Combination”). In connection with the closing of the Business Combination, Pivotal Investment Corporation II changed its name to XL Fleet Corp. Acquisition of World Energy: On May 17, 2021 (“Closing Date”), the Company acquired 100% of the membership interests of World Energy Efficiency Services, LLC (“World Energy”). World Energy provides turnkey energy efficiency, renewable technology, electric vehicle charging stations and other energy solutions throughout New England. The Company completed the acquisition to further the strategy of its XL Grid business to provide a suite of charging and power solutions to support fleet electrification (See Note 4). Investment in eNow: On July 15, 2021, XL Fleet purchased a minority interest in eNow Inc. (“eNow”), a provider of solar and battery power systems that enable fully-electric transport refrigeration units (eTRUs) for commercial semi-trailers. In connection with this investment, XL Fleet entered into a development and supply agreement with eNow (See Note 15). COVID-19 Worldwide Pandemic: On March 11, 2020, the World Health Organization characterized the outbreak of the novel coronavirus (“COVID-19”) as a global pandemic and recommended containment and mitigation measures. Since then, extraordinary actions have been taken by international, federal, state, and local public health and governmental authorities to contain and combat the outbreak and spread of COVID-19 in regions throughout the world. These actions include travel bans, quarantines, “stay-at-home” orders, and similar mandates for many individuals to substantially restrict daily activities and for many businesses to curtail or cease normal operations. Consistent with the actions taken by governmental authorities, the Company has taken appropriately cautious steps to protect its workforce and support community efforts. As part of these efforts, and in accordance with applicable government directives, beginning in late March 2020, the Company implemented work from home policies where practical at its facilities. Effective June 30, 2021 all 150 employees were working full-time from one of the Company’s five offices or from home. Current COVID-19 policies include universal facial covering requirements if not vaccinated, rearranging facilities to follow social distancing protocols, employees self-screening before going into the office, enhanced cleaning procedures, ability to go mask-free if proof of vaccination is provided to Human Resources, and strict quarantine protocols for any suspected or confirmed employee cases. However, the COVID-19 pandemic and the continued precautionary actions taken related to COVID-19 have adversely impacted, and are expected to continue to adversely impact, its operations, its contractors and the automotive original equipment manufacturers. The Company has experienced, and expects to continue to experience, reduced operations and production line shutdowns at vehicle OEMs due to COVID-19, limitations on travel by the Company’s personnel and personnel of the Company’s customers, and future delays or shutdowns of vehicle OEMs or the Company’s suppliers. The COVID-19 pandemic and the protocols and procedures the Company has implemented in response to the pandemic have caused some delays in operational activities. The full impact of the COVID-19 pandemic on its business and results of operations subsequent to June 30, 2021 will depend on future developments, such as the ultimate duration and scope of the outbreak and its impact on its operations and impact on its customers and industry partners.	Note 1. Organization, Description of Business and Liquidity Description of Business: XL Fleet Corp. and its subsidiaries (“XL Fleet” or the “Company”) is a leading provider of fleet electrification solutions for commercial vehicles in North America, with over 4,300 electrified powertrain systems sold and driven over 140 million miles by over 200 fleets, as of December 31, 2020. XL Fleet’s vision is to become the world leader in fleet electrification solutions, with a mission of accelerating the adoption of fleet electrification systems through cost effective, customer tailored and comprehensive solutions. Merger and Organization: On December 21, 2020 (the “Closing Date”), privately held XL Hybrids, Inc., a Delaware corporation, (“Legacy XL”) consummated the merger pursuant to that certain Agreement and Plan of Reorganization, dated as of September 17, 2020 (the “Merger Agreement”), by and among Pivotal Investment Corporation II (“Pivotal”), PIC II Merger Sub Corp., a Delaware corporation and wholly owned subsidiary of Pivotal (“Merger Sub”), and Legacy XL. Pursuant to the terms of the Merger Agreement, a business combination between Legacy XL and Pivotal was effected through the merger of Merger Sub with and into Legacy XL, with Legacy XL surviving as a wholly-owned subsidiary of Pivotal (the “Merger” and, collectively with the other transactions described in the Merger Agreement, the “Business Combination”). On the Closing Date, and in connection with the closing of the Business Combination (the “Closing”), Pivotal Investment Corporation II changed its name to XL Fleet Corp. (“XL Fleet Corp.”) (See Note 4). COVID-19 Worldwide Pandemic: On March 11, 2020, the World Health Organization characterized the outbreak of the novel coronavirus (“COVID-19”) as a global pandemic and recommended containment and mitigation measures. Since then, extraordinary actions have been taken by international, federal, state, and local public health and governmental authorities to contain and combat the outbreak and spread of COVID-19 in regions throughout the world. These actions include travel bans, quarantines, “stay-at-home” orders, and similar mandates for many individuals to substantially restrict daily activities and for many businesses to curtail or cease normal operations. Consistent with the actions taken by governmental authorities, the Company has taken appropriately cautious steps to protect its workforce and support community efforts. As part of these efforts, and in accordance with applicable government directives, the Company initially implemented work from home policies where practical at its facilities in late March 2020. Starting late March 2020, approximately 40 of its employees were able to complete their duties from home, which enabled much critical work to continue. The remaining 19 members of its workforce were unable to perform their normal duties from home. In April 2020, the Company resumed limited operations under revised operational and manufacturing plans that conform to the latest COVID-19 health precautions. This includes universal facial covering requirements, rearranging facilities to follow social distancing protocols, conducting regular temperature checks and undertaking regular and thorough disinfecting of surfaces and tools. However, the COVID-19 pandemic and the continued precautionary actions taken related to COVID-19 have adversely impacted, and are expected to continue to adversely impact, its operations, its contractors and the automotive original equipment manufacturers. The Company has experienced, and expects to continue to experience, reduced operations and production line shutdowns at vehicle OEMs due to COVID-19, limitations on travel by the Company’s personnel and personnel of the Company’s customers, and future delays or shutdowns of vehicle OEMs or the Company’s suppliers. The COVID-19 pandemic and the protocols and procedures the Company has implemented in response to the pandemic have caused some delays in operational activities. The full impact of the COVID-19 pandemic on its business and results of operations subsequent to December 31, 2020 will depend on future developments, such as the ultimate duration and scope of the outbreak and its impact on its operations and impact on its customers and industry partners. Liquidity: The Company believes its cash and cash equivalents on hand at December 31, 2020 and management’s operating plan, will provide sufficient liquidity to fund its operations for at least the next twelve months from the issuance of these financial statements.

Organization and Description of Business

6 Months Ended

12 Months Ended

Jun. 30, 2021

Dec. 31, 2020

Organization and Description of Business

Note 1. Organization and Description of Business

Description of Business: XL Fleet Corp. and its subsidiaries (“XL Fleet” or the “Company”) is a leading provider of fleet electrification solutions for commercial vehicles in North America, offering solutions for vehicle electrification (“Drive Systems”) and infrastructure solutions such as vehicle charging stations through its XL Grid programs, as further described below. XL Fleet has over 4,400 electrified powertrain systems sold and driven over 160 million miles by over 235 fleets, as of June 30, 2021. XL Fleet’s vision is to become the world leader in commercial fleet electrification solutions, with a mission of accelerating the adoption of fleet electrification systems through cost effective, customer tailored and comprehensive solutions.

Merger and Reorganization: On December 21, 2020, privately held XL Hybrids, Inc., a Delaware corporation, (“Legacy XL”) consummated the merger pursuant to that certain Agreement and Plan of Reorganization, dated as of September 17, 2020 (the “Merger Agreement”), by and among Pivotal Investment Corporation II (“Pivotal”), PIC II Merger Sub Corp., a Delaware corporation and wholly owned subsidiary of Pivotal (“Merger Sub”), and Legacy XL. Pursuant to the terms of the Merger Agreement, a business combination between Legacy XL and Pivotal was effected through the merger of Merger Sub with and into Legacy XL, with Legacy XL surviving as a wholly-owned subsidiary of Pivotal (the “Merger” and, collectively with the other transactions described in the Merger Agreement, the “Business Combination”). In connection with the closing of the Business Combination, Pivotal Investment Corporation II changed its name to XL Fleet Corp.

Acquisition of World Energy: On May 17, 2021 (“Closing Date”), the Company acquired 100% of the membership interests of World Energy Efficiency Services, LLC (“World Energy”). World Energy provides turnkey energy efficiency, renewable technology, electric vehicle charging stations and other energy solutions throughout New England. The Company completed the acquisition to further the strategy of its XL Grid business to provide a suite of charging and power solutions to support fleet electrification (See Note 4).

Investment in eNow: On July 15, 2021, XL Fleet purchased a minority interest in eNow Inc. (“eNow”), a provider of solar and battery power systems that enable fully-electric transport refrigeration units (eTRUs) for commercial semi-trailers. In connection with this investment, XL Fleet entered into a development and supply agreement with eNow (See Note 15).

COVID-19 Worldwide Pandemic: On March 11, 2020, the World Health Organization characterized the outbreak of the novel coronavirus (“COVID-19”) as a global pandemic and recommended containment and mitigation measures. Since then, extraordinary actions have been taken by international, federal, state, and local public health and governmental authorities to contain and combat the outbreak and spread of COVID-19 in regions throughout the world. These actions include travel bans, quarantines, “stay-at-home” orders, and similar mandates for many individuals to substantially restrict daily activities and for many businesses to curtail or cease normal operations.

Consistent with the actions taken by governmental authorities, the Company has taken appropriately cautious steps to protect its workforce and support community efforts. As part of these efforts, and in accordance with applicable government directives, beginning in late March 2020, the Company implemented work from home policies where practical at its facilities. Effective June 30, 2021 all 150 employees were working full-time from one of the Company’s five offices or from home. Current COVID-19 policies include universal facial covering requirements if not vaccinated, rearranging facilities to follow social distancing protocols, employees self-screening before going into the office, enhanced cleaning procedures, ability to go mask-free if proof of vaccination is provided to Human Resources, and strict quarantine protocols for any suspected or confirmed employee cases. However, the COVID-19 pandemic and the continued precautionary actions taken related to COVID-19 have adversely impacted, and are expected to continue to adversely impact, its operations, its contractors and the automotive original equipment manufacturers.

The Company has experienced, and expects to continue to experience, reduced operations and production line shutdowns at vehicle OEMs due to COVID-19, limitations on travel by the Company’s personnel and personnel of the Company’s customers, and future delays or shutdowns of vehicle OEMs or the Company’s suppliers.

The COVID-19 pandemic and the protocols and procedures the Company has implemented in response to the pandemic have caused some delays in operational activities. The full impact of the COVID-19 pandemic on its business and results of operations subsequent to June 30, 2021 will depend on future developments, such as the ultimate duration and scope of the outbreak and its impact on its operations and impact on its customers and industry partners.

Note 1. Organization, Description of Business and Liquidity

Description of Business: XL Fleet Corp. and its subsidiaries (“XL Fleet” or the “Company”) is a leading provider of fleet electrification solutions for commercial vehicles in North America, with over 4,300 electrified powertrain systems sold and driven over 140 million miles by over 200 fleets, as of December 31, 2020. XL Fleet’s vision is to become the world leader in fleet electrification solutions, with a mission of accelerating the adoption of fleet electrification systems through cost effective, customer tailored and comprehensive solutions.

Merger and Organization: On December 21, 2020 (the “Closing Date”), privately held XL Hybrids, Inc., a Delaware corporation, (“Legacy XL”) consummated the merger pursuant to that certain Agreement and Plan of Reorganization, dated as of September 17, 2020 (the “Merger Agreement”), by and among Pivotal Investment Corporation II (“Pivotal”), PIC II Merger Sub Corp., a Delaware corporation and wholly owned subsidiary of Pivotal (“Merger Sub”), and Legacy XL. Pursuant to the terms of the Merger Agreement, a business combination between Legacy XL and Pivotal was effected through the merger of Merger Sub with and into Legacy XL, with Legacy XL surviving as a wholly-owned subsidiary of Pivotal (the “Merger” and, collectively with the other transactions described in the Merger Agreement, the “Business Combination”). On the Closing Date, and in connection with the closing of the Business Combination (the “Closing”), Pivotal Investment Corporation II changed its name to XL Fleet Corp. (“XL Fleet Corp.”) (See Note 4).

Consistent with the actions taken by governmental authorities, the Company has taken appropriately cautious steps to protect its workforce and support community efforts. As part of these efforts, and in accordance with applicable government directives, the Company initially implemented work from home policies where practical at its facilities in late March 2020. Starting late March 2020, approximately 40 of its employees were able to complete their duties from home, which enabled much critical work to continue. The remaining 19 members of its workforce were unable to perform their normal duties from home. In April 2020, the Company resumed limited operations under revised operational and manufacturing plans that conform to the latest COVID-19 health precautions. This includes universal facial covering requirements, rearranging facilities to follow social distancing protocols, conducting regular temperature checks and undertaking regular and thorough disinfecting of surfaces and tools. However, the COVID-19 pandemic and the continued precautionary actions taken related to COVID-19 have adversely impacted, and are expected to continue to adversely impact, its operations, its contractors and the automotive original equipment manufacturers.

The COVID-19 pandemic and the protocols and procedures the Company has implemented in response to the pandemic have caused some delays in operational activities. The full impact of the COVID-19 pandemic on its business and results of operations subsequent to December 31, 2020 will depend on future developments, such as the ultimate duration and scope of the outbreak and its impact on its operations and impact on its customers and industry partners.

Liquidity: The Company believes its cash and cash equivalents on hand at December 31, 2020 and management’s operating plan, will provide sufficient liquidity to fund its operations for at least the next twelve months from the issuance of these financial statements.