Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Mar. 27, 2019	Jun. 29, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	ENDOLOGIX INC /DE/
Entity Central Index Key	0001013606
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		10,347,913
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Public Float			$ 479,442,894
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false