Document and Entity Information (USD $)	6 Months Ended
	Sep. 30, 2012	Oct. 22, 2012	Sep. 30, 2011
Document And Entity Information
Entity Registrant Name	8X8 INC /DE/
Entity Central Index Key	0001023731
Document Type	10-Q
Document Period End Date	Sep. 30, 2012
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			$ 276,930,119
Entity Common Stock, Shares Outstanding		71,470,617
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2013