Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 23, 2018
Entity Information
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Trading Symbol	FB
Entity Registrant Name	Facebook Inc
Entity Central Index Key	0001326801
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Class A Common Stock
Entity Information
Entity Common Stock, Shares Outstanding		2,398,606,201
Class B Common Stock
Entity Information
Entity Common Stock, Shares Outstanding		496,021,547