Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 24, 2020	Jun. 30, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	000-30141
Entity Registrant Name	LIVEPERSON, INC.
Entity Central Index Key	0001102993
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3861628
Entity Address, Address Line One	475 Tenth Avenue, 5th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10018
City Area Code	212
Local Phone Number	609-4200
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	LPSN
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 1,207,203,816
Entity Common Stock, Shares Outstanding		64,108,516
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement for the 2020 Annual Meeting of Stockholders, which we plan to file subsequent to the date hereof, are incorporated by reference into Items 10, 11, 12, 13 and 14 of Part III of this Form 10-K.