Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 21, 2020	Jun. 28, 2019
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-38846
Entity Registrant Name	Lyft, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-8809830
Entity Address, Address Line One	185 Berry Street,
Entity Address, Address Line Two	Suite 5000
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94107
City Area Code	844
Local Phone Number	250-2773
Title of 12(b) Security	Class A common stock, par value of $0.00001 per share
Trading Symbol	LYFT
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 14.1
Documents Incorporated by Reference	Portions of the registrant’s Proxy Statement for the 2020 Annual Meeting of Stockholders are incorporated herein by reference in Part III of this Annual Report on Form 10-K to the extent stated herein. Such proxy statement will be filed with the Securities and Exchange Commission within 120 days of the registrant’s fiscal year ended December 31, 2019.
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Central Index Key	0001759509
Current Fiscal Year End Date	--12-31
Class A Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		297,836,880
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		8,802,629