Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Nov. 02, 2023
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2023
Document Fiscal Year Focus	2023
Securities Act File Number	001-33480
Entity Registrant Name	CLEAN ENERGY FUELS CORP.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0968580
Entity Address, Address Line One	4675 MacArthur Court
Entity Address, Address Line Two	Suite 800
Entity Address, City or Town	Newport Beach
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92660
City Area Code	949
Local Phone Number	437-1000
Title of 12(b) Security	Common stock, $0.0001 par value per share
Trading Symbol	CLNE
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		223,020,351
Entity Central Index Key	0001368265
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q3
Amendment Flag	false