Document and Entity Information (USD $)	9 Months Ended
	Dec. 31, 2011	Jan. 18, 2012	Sep. 30, 2010
Document And Entity Information
Entity Registrant Name	8X8 INC /DE/
Entity Central Index Key	0001023731
Document Type	10-Q
Document Period End Date	Dec. 31, 2011
Amendment Flag	false
Current Fiscal Year End Date	--03-31
Is Entity a Well-known Seasoned Issuer?	No
Is Entity a Voluntary Filer?	No
Is Entity's Reporting Status Current?	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 131,529,107
Entity Common Stock, Shares Outstanding		69,536,277
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2012