DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	9 Months Ended
Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Company Information Groupon, Inc. and subsidiaries, which commenced operations in October 2008, operates online local commerce marketplaces throughout the world that connect merchants to consumers by offering goods and services, generally at a discount. Customers access those marketplaces through our websites, primarily localized groupon.com sites in many countries, and our mobile applications. Our operations are organized into two segments: North America and International. See Note 16, Segment Information. Unaudited Interim Financial Information We have prepared the accompanying condensed consolidated financial statements pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC") for interim financial reporting. These condensed consolidated financial statements are unaudited and, in our opinion, include all adjustments, consisting of normal recurring adjustments and accruals, necessary for a fair presentation of the condensed consolidated balance sheets, statements of operations, comprehensive income (loss), cash flows and stockholders' equity for the periods presented. Operating results for the periods presented are not necessarily indicative of the results to be expected for the full year ending December 31, 2018. Certain information and disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP") have been omitted in accordance with the rules and regulations of the SEC. These condensed consolidated financial statements and notes should be read in conjunction with the audited consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended December 31, 2017, filed with the SEC on February 14, 2018, as amended by the Form 10-K/A for the year ended December 31, 2017, filed with the SEC on March 23, 2018. Principles of Consolidation The condensed consolidated financial statements include the accounts of Groupon, Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The condensed consolidated financial statements were prepared in accordance with U.S. GAAP and include the assets, liabilities, revenue and expenses of all wholly-owned subsidiaries and majority-owned subsidiaries over which we exercise control and variable interest entities for which we have determined that we are the primary beneficiary. Outside stockholders' interests in subsidiaries are shown on the condensed consolidated financial statements as Noncontrolling interests. Equity investments in entities in which we do not have a controlling financial interest are accounted for under the equity method, the fair value option, as available-for-sale securities or at cost adjusted for observable price changes and impairments, as appropriate. Reclassifications and Terminology Changes Certain reclassifications have been made to the condensed consolidated financial statements of prior periods and the accompanying notes to conform to the current period presentation, including the change in presentation of restricted cash in the condensed consolidated statements of cash flows upon adoption of ASU 2016-18. Refer to Note 2, Adoption of New Accounting Standards, for additional information. Additionally, in prior years, we referred to our product revenue and service revenue as "direct revenue" and "third-party and other revenue," respectively. This terminology change did not impact the amounts presented in the condensed consolidated financial statements. Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires estimates and assumptions that affect the reported amounts and classifications of assets and liabilities, revenue and expenses, and the related disclosures of contingent liabilities in the condensed consolidated financial statements and accompanying notes. Estimates are used for, but not limited to, variable consideration from unredeemed vouchers, income taxes, valuation of goodwill and intangible assets, investments, customer refunds, contingent liabilities and the useful lives of property, equipment and software and intangible assets. Actual results could differ materially from those estimates.

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION

Company Information

Groupon, Inc. and subsidiaries, which commenced operations in October 2008, operates online local commerce marketplaces throughout the world that connect merchants to consumers by offering goods and services, generally at a discount. Customers access those marketplaces through our websites, primarily localized groupon.com sites in many countries, and our mobile applications.

Our operations are organized into two segments: North America and International. See Note 16, Segment Information.

Unaudited Interim Financial Information

We have prepared the accompanying condensed consolidated financial statements pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC") for interim financial reporting. These condensed consolidated financial statements are unaudited and, in our opinion, include all adjustments, consisting of normal recurring adjustments and accruals, necessary for a fair presentation of the condensed consolidated balance sheets, statements of operations, comprehensive income (loss), cash flows and stockholders' equity for the periods presented. Operating results for the periods presented are not necessarily indicative of the results to be expected for the full year ending December 31, 2018. Certain information and disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP") have been omitted in accordance with the rules and regulations of the SEC. These condensed consolidated financial statements and notes should be read in conjunction with the audited consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended December 31, 2017, filed with the SEC on February 14, 2018, as amended by the Form 10-K/A for the year ended December 31, 2017, filed with the SEC on March 23, 2018.

Principles of Consolidation

The condensed consolidated financial statements include the accounts of Groupon, Inc. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The condensed consolidated financial statements were prepared in accordance with U.S. GAAP and include the assets, liabilities, revenue and expenses of all wholly-owned subsidiaries and majority-owned subsidiaries over which we exercise control and variable interest entities for which we have determined that we are the primary beneficiary. Outside stockholders' interests in subsidiaries are shown on the condensed consolidated financial statements as Noncontrolling interests. Equity investments in entities in which we do not have a controlling financial interest are accounted for under the equity method, the fair value option, as available-for-sale securities or at cost adjusted for observable price changes and impairments, as appropriate.

Reclassifications and Terminology Changes

Certain reclassifications have been made to the condensed consolidated financial statements of prior periods and the accompanying notes to conform to the current period presentation, including the change in presentation of restricted cash in the condensed consolidated statements of cash flows upon adoption of ASU 2016-18. Refer to Note 2, Adoption of New Accounting Standards, for additional information. Additionally, in prior years, we referred to our product revenue and service revenue as "direct revenue" and "third-party and other revenue," respectively. This terminology change did not impact the amounts presented in the condensed consolidated financial statements.

Use of Estimates

The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires estimates and assumptions that affect the reported amounts and classifications of assets and liabilities, revenue and expenses, and the related disclosures of contingent liabilities in the condensed consolidated financial statements and accompanying notes. Estimates are used for, but not limited to, variable consideration from unredeemed vouchers, income taxes, valuation of goodwill and intangible assets, investments, customer refunds, contingent liabilities and the useful lives of property, equipment and software and intangible assets. Actual results could differ materially from those estimates.