Cover Document - shares	9 Months Ended
	Sep. 30, 2017	Oct. 30, 2017
Entity Registrant Name	Groupon, Inc.
Entity Central Index Key	0001490281
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Common Stock, Shares, Outstanding		558,403,052
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes