Financial Statement Information Policies (Policies)	6 Months Ended
Financial Statement Information Policies (Policies)	Jun. 30, 2012
FINANCIAL STATEMENT INFORMATION [Abstract]
Use of Estimates, Policy [Policy Text Block]	The preparation of 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 utilized for, but not limited to, stock‑based compensation, income taxes, valuation of acquired goodwill and intangible assets, customer refunds, contingent liabilities and the depreciable lives of fixed assets. Actual results could differ materially from those estimates.
Revenue Recognition, Policy [Policy Text Block]	Revenue The Company recognizes revenue when the following criteria are met: persuasive evidence of an arrangement exists; delivery has occurred; the selling price is fixed or determinable; and collectability is reasonably assured. Third party revenue recognition The Company generates third party revenue, where it acts as the third party agent, by offering goods and services at a discount through its local commerce marketplace that connects merchants to consumers. The Company's marketplace includes deals offered through a variety of channels including: Featured Daily Deals, National Deals, Groupon Now!, Groupon Goods, Groupon Getaways and GrouponLive. Customers purchase Groupons from the Company and redeem them with the Company's merchant partners. The revenue recognition criteria are met when the number of customers who purchase the deal exceeds the predetermined threshold (where applicable), the Groupon has been electronically delivered to the purchaser and a listing of Groupons sold has been made available to the merchant. At that time, the Company's obligations to the merchant, for which it is serving as an agent, are substantially complete. The Company's remaining obligations, which are limited to remitting payment to the merchant and continuing to make available on the Company's website the listing of Groupons sold previously provided to the merchant, are inconsequential or perfunctory. The Company records as revenue the net amount it retains from the sale of Groupons after paying an agreed upon percentage of the purchase price to the featured merchant, excluding any applicable taxes. Revenue is recorded on a net basis because the Company is acting as an agent of the merchant in the transaction. The Company evaluates whether it is appropriate to record the gross amount of its Groupon Goods sales and related costs by considering a number of factors, including, among other things, whether the Company is the primary obligor under the arrangement, has inventory risk, and has latitude in establishing prices. For Groupon Goods transactions where the Company is performing a service by acting as the agent of the merchant responsible for fulfillment, revenue is recorded on a net basis. Direct revenue recognition Direct revenue is derived primarily from selling products through the Company's Groupon Goods channel where the Company is the merchant of record. The Company is the primary obligor in these transactions, is subject to inventory risk and has latitude in establishing prices. Accordingly, direct revenue is recorded on a gross basis. Direct revenue, including associated shipping revenue, is recorded when the products are shipped and title passes to customers. The Company recognized no direct revenue for the six months ended June 30, 2011.
Cost of Sales, Policy [Policy Text Block]	Cost of revenue Cost of revenue is composed of direct and indirect costs incurred to generate revenue, including costs related to credit card processing fees, refunds provided to customers which are not recoverable from the merchant, certain technology costs, editorial costs, other processing fees and the purchase price of consumer products where the Company is selling the product as the merchant of record and outbound shipping charges. Credit card and other processing fees are expensed as incurred. At the time of sale, the Company records a liability for estimated costs to provide refunds which are not recoverable from the merchant based upon the nature of the product or service and historical experience. Technology costs in cost of revenue consist of a portion of the payroll and stock‑based compensation expense related to the Company's technology support personnel who are responsible for operating and maintaining the infrastructure of the Company's existing website. Such technology costs also include website hosting and email distribution costs. Editorial costs consist of a portion of the payroll and stock‑based compensation expense related to the Company's editorial personnel, as such staff is primarily dedicated to drafting and promoting merchant deals. Purchase price of consumer products related to direct revenue is included in the Company's inventory and recognized along with outbound shipping charges as cost of revenue upon sale and delivery of the products to customers.
Investment, Policy [Policy Text Block]	Cost method investments Nonmarketable equity investments for which the Company does not have the ability to exercise significant influence are accounted for using the cost method of accounting and classified as “Other non-current assets” on the condensed consolidated balance sheets. Under the cost method, investments are carried at cost and are adjusted only for other-than-temporary declines in fair value, certain distributions and additional investments. The Company evaluates the investments for impairment annually or more frequently when a triggering event occurs.
Revenue Recognition, Sales Returns [Policy Text Block]	Refunds The Company estimates future refunds utilizing a statistical model that incorporates the following data inputs and factors: historical refund experience developed from millions of deals featured on the Company's website, the relative risk of refund based on expiration date, deal value, deal category and other qualitative factors that could impact the level of future refunds, such as introductions of new deals, discontinuations of legacy deals, expected change, if any, in Company practices in response to refund experience or economic trends that might impact customer demand. In early 2012, actual refund activity for deals featured late in 201l was demonstrating a consistent trend that was deviating from the modeled refund behavior, due in part to a shift in fourth quarter deal mix and higher price point offers. Accordingly, the Company updated its refund model to better capture variations in trends in its business. By continually refining the refund model to reflect such data inputs as discussed above, the Company believes its model enables it to track and anticipate refund behavior. The Company accrues costs associated with refunds in accrued expenses on the condensed consolidated balance sheets. The cost of refunds for third party revenue where the amount payable to the merchant is recoverable and for all direct revenue is presented in the condensed consolidated statements of operations as a reduction to revenue. The cost of refunds for third party revenue when there is no amount recoverable from the merchant is presented as a cost of revenue. The Company assesses the trends that could affect its estimates and makes changes to the refund reserve quarterly when it appears refunds may differ from our original estimates. If actual results are not consistent with the estimates or assumptions stated above, the Company may need to change its future estimates and the effects could be material to the consolidated financial statements.

Disclosure of accounting policy for recognition of costs in the period which correspond to the sales and revenue categories presented in the statement of operations. The accounting policy may include the amount and nature of costs incurred, provisions associated with inventories, purchase discounts, freight and other costs included in cost of sales incurred and recorded in the period. This disclosure also includes the nature of costs of sales incurred and recorded in the statement of operations for the period relating to transactions with related parties.

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- Definition

Disclosure of accounting policy for investments in financial assets, including marketable securities (debt and equity securities with readily determinable fair values), investments accounted for under the equity method and cost method, securities borrowed and loaned, and repurchase and resale agreements. For marketable securities, the disclosure may include the entity's accounting treatment for transfers between investment categories and how the fair values for such securities are determined. Also, for all investments, an entity may describe its policy for assessing, recognizing and measuring impairment of the investment.

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- Definition

Disclosure of accounting policy for revenue recognition. If the entity has different policies for different types of revenue transactions, the policy for each material type of transaction is generally disclosed. If a sales transaction has multiple element arrangements (for example, delivery of multiple products, services or the rights to use assets) the disclosure may indicate the accounting policy for each unit of accounting as well as how units of accounting are determined and valued. The disclosure may encompass important judgment as to appropriateness of principles related to recognition of revenue. The disclosure also may indicate the entity's treatment of any unearned or deferred revenue that arises from the transaction.

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- Definition

Disclosure of accounting policy for sales returns.

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- Definition

Disclosure of accounting policy for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles.

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