Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 28, 2014	Jun. 30, 2013
Document - Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Trading Symbol	lpsn
Entity Registrant Name	LIVEPERSON INC
Entity Central Index Key	0001102993
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		54,720,689
Entity Public Float			$ 446,033,101