Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 02, 2018
Document Information [Line Items]
Entity Registrant Name	Bloom Energy Corp
Entity Central Index Key	0001664703
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Emerging Growth Company	true
Entity Small Business	false
Entity Ex Transition Period	false
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		20,865,308
Class B common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		88,551,155