| Cover Page | Jan. 31, 2020 |
| Cover page. | |
| Document Type | 8-K |
| Document Period End Date | Jan. 31, 2020 |
| Entity Registrant Name | Groupon, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 27-0903295 |
| Entity Address, Address Line One | 600 W Chicago Avenue |
| Entity Address, Address Line Two | Suite 400 |
| Entity Address, City or Town | Chicago |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60654 |
| City Area Code | (312) |
| Local Phone Number | 334-1579 |
| Entity File Number | 1-35335 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common stock, par value $0.0001 per share |
| Trading Symbol | GRPN |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001490281 |
| Amendment Flag | false |
