DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Policies)	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of Groupon, Inc. and its wholly-owned subsidiaries, majority-owned subsidiaries over which we exercise control and variable interest entities for which we are the primary beneficiary. All intercompany accounts and transactions have been eliminated in consolidation. Outside stockholders' interests in subsidiaries are shown on the condensed consolidated financial statements as Noncontrolling interests. Investments in entities in which we do not have a controlling financial interest are accounted for at fair value, as available-for-sale securities or at cost adjusted for observable price changes and impairments, as appropriate.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles ("GAAP") requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Estimates in our financial statements include, but are not limited to, the following: variable consideration from unredeemed vouchers; income taxes; leases; initial valuation and subsequent impairment testing of goodwill, other intangible assets and long-lived assets; investments; receivables; customer refunds and other reserves; contingent liabilities; and the useful lives of property, equipment and software and intangible assets. Actual results could differ materially from those estimates.
Reclassifications	Reclassifications Certain reclassifications have been made to the condensed consolidated financial statements of prior periods to conform to the current period presentation.
Adoption of New Accounting Standards	Adoption of New Accounting Standards We early adopted the guidance in ASU 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity, on January 1, 2021. The ASU removes the separation models for convertible debt with a cash conversion feature or convertible instruments with a beneficial conversion feature. Additionally, the ASU removes certain conditions for equity classification related to contracts in an entity’s own equity (e.g., warrants) and amends certain guidance related to the computation of income (loss) per share for convertible instruments and contracts in an entity’s own equity. Prior to the adoption of ASU 2020-06, we separated the convertible senior notes due 2022 (the "Atairos Notes") into their liability and equity components. Following the adoption of ASU 2020-06, the previously bifurcated equity component of the Atairos Notes was recombined with the liability component, resulting in a single liability-classified instrument. The carrying value of the Atairos Notes at transition was determined by recalculating the basis of the Atairos Notes as if the conversion option had not been bifurcated at issuance. Transaction costs related to the issuance of the Atairos Notes that were allocated to the equity component were reclassified out of Additional paid-in-capital and the amortization and the related debt discount associated with these costs was recalculated through the transition date. The transaction costs were recorded as a debt discount in the condensed consolidated balance sheets and amortized to interest expense over the remaining term of the Atairos Notes. Together with the cash interest, this resulted in an effective interest rate of 3.76%. As a result of adopting ASU 2020-06, in the first quarter of 2021, we recorded a $67.0 million net reduction to additional paid-in capital, a $19.0 million increase to Convertible senior notes, net and a $48.0 million reduction to our opening accumulated deficit as of January 1, 2021. In the fourth quarter of 2021, we recorded an additional $2.7 million adjustment to our opening accumulated deficit and additional paid-in capital related to tax impacts of our bond hedges.