Cover Page - shares	6 Months Ended
	Jun. 30, 2022	Oct. 13, 2022
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2022
Current Fiscal Year End Date	--12-31
Entity Registrant Name	Legacy EJY, Inc.
Entity Central Index Key	0001830180
Entity Tax Identification Number	98-1566891
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity File Number	001-39800
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	3240 Hillview Avenue
Entity Address, City or Town	Palo Alto
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94304
City Area Code	888
Local Phone Number	463-6569
Document Transition Report	false
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		121,803,181
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common stock, $0.0001 par value per share
Trading Symbol	ENJYQ
Warrant [Member]
Document Information [Line Items]
Title of 12(b) Security	Warrants to purchase common stock
Trading Symbol	ENJYWQ