Description of Business and Basis of Presentation	9 Months Ended
Description of Business and Basis of Presentation	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation Organization and Description of Business Lyft, Inc. (the “Company” or “Lyft”) is incorporated in Delaware with its headquarters in San Francisco, California. The Company operates multimodal transportation networks in the United States and Canada that offer access to a variety of transportation options through the Company’s platform and mobile-based applications. This network enables multiple modes of transportation including the facilitation of peer-to-peer ridesharing by connecting drivers who have a vehicle with passengers who need a ride. The Company’s proprietary technology platform (the “Lyft Platform”) provides a marketplace where drivers can be matched with passengers via the Lyft mobile application (the “App”) where the Company operates as a Transportation Network Company (“TNC”). Transportation options through the Company’s platform and mobile-based applications are substantially comprised of its ridesharing marketplace that connects drivers and riders in cities across the United States and in select cities in Canada, Lyft’s network of shared bikes and scooters ("Light Vehicles"), the Express Drive program which is a flexible vehicle rental program for users who want to drive using the Lyft Platform but do not have access to a vehicle that meets Lyft's requirements, and Lyft Rentals, a consumer offering for users who want to rent a car for a fixed period of time for personal use. Transfer of Certain Legacy Auto Liability Insurance On March 31, 2020, the Company’s wholly-owned subsidiary, Pacific Valley Insurance Company, Inc. (“PVIC”), entered into a Novation Agreement (the “Novation”) with Clarendon National Insurance Company, a subsidiary of Enstar Group Limited (“Clarendon”), and certain underwriting companies of Zurich North America (“Zurich”). Pursuant to the terms of the Novation, on the effective date March 31, 2020, the obligations of PVIC as reinsurer to Zurich for certain legacy auto liability insurance business underwritten between October 1, 2015 and September 30, 2018 ("Legacy Auto Liability"), were assigned to, assumed by, and novated to Clarendon, for cash consideration of $465.0 million. The Company paid the $465.0 million cash consideration to Clarendon on April 3, 2020 which is the date when certain Clarendon trust agreements were executed and the trust accounts were established in order to secure the applicable payments subject to Novation. In conjunction with the Novation, Clarendon and PVIC executed a binding letter of intent to enter into an Excess of Loss Retrocession Agreement (“Retrocession Agreement”). The Retrocession Agreement was executed in July 2020 with an effective date of March 31, 2020. The execution of the Retrocession Agreement did not have a material impact on the condensed consolidated financial statements as of September 30, 2020. Refer to Note 4 “Supplemental Financial Statement Information” to the condensed consolidated financial statements for information regarding this transaction. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and the requirements of the U.S. Securities and Exchange Commission (the “SEC”) for interim reporting. The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The condensed consolidated balance sheet as of December 31, 2019 included herein was derived from the audited financial statements as of that date. The accompanying unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to state fairly the Company’s financial position, results of operations, comprehensive loss, redeemable convertible preferred stock and stockholders’ equity (deficit), and cash flows for the periods presented, but are not necessarily indicative of the results of operations to be anticipated for any future annual or interim period.