Summary of significant accounting policies (Policies)	3 Months Ended
Summary of significant accounting policies (Policies)	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of preparation and liquidity	The accompanying unaudited condensed consolidated financial statements have been prepared by Fluent, Inc., a Delaware corporation (the "Company" or "Fluent"), in accordance with accounting principles generally accepted in the United States ("US GAAP") and applicable rules and regulations of the Securities and Exchange Commission (the "SEC") regarding interim financial reporting. Certain information and note disclosures normally included in annual financial statements prepared in accordance with US GAAP have been condensed or omitted pursuant to those rules and regulations. The accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for any future interim periods or for the full year ending December 31, 2019. The information included in this quarterly report on Form 10-Q should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 ("2018 Form 10-K") filed with the SEC on March 18, 2019. The condensed consolidated balance sheet as of December 31, 2018 included herein was derived from the audited financial statements as of that date included in the 2018 Form 10-K.
Principles of consolidation	The condensed consolidated financial statements include the financial statements of the Company and its subsidiaries. All significant transactions among the Company and its subsidiaries have been eliminated upon consolidation.
Reclassification	During the year ended December 31, 2018, the Company reviewed its classification of certain expenses in its consolidated statement of operations in an effort to bring added transparency and conformity to its reporting. As a result of this review, the Company made a number of changes to the way it classifies operating expenses. Expenses for prior periods have been reclassified to conform to the current period presentation. For the three months ended March 31, 2018, the reclassifications had no effect on loss from operations, net loss from continuing operations, or net loss.
Recently issued and adopted accounting standards	In February 2016, the Financial Accounting Standards Board ("FASB") issued ASU No. 2016-02 ("ASU 2016-02"), Leases (Topic 842), and additional changes, modifications, clarifications or interpretations thereafter, which generally require companies to recognize operating and financing lease liabilities and corresponding right-of-use assets on the balance sheet. Effective January 1, 2019, the Company adopted ASU 2016-02 using a modified retrospective approach, utilizing transition guidance introduced in ASU 2018-11, Leases: Targeted Improvements, and elected the ‘package of practical expedients,’ which permits the Company not to reassess prior conclusions about lease identification, classification and initial direct costs. As of January 1, 2019, the adoption of ASU 2016-02 resulted in the recording of right-of-use assets and operating lease liabilities of $10,866 and $11,138, respectively, on the condensed consolidated balance sheets. The difference between the right-of-use assets and operating lease liabilities was recorded as a write-off of the previously recognized deferred rent liability included in accrued expenses and other current liabilities on the condensed consolidated balance sheets. The standard did not impact the Company's condensed consolidated statements of operations or condensed consolidated statements of cash flows. The accounting for financing leases, previously referred to as capital leases, remained unchanged as a result of the adoption of this guidance. Subsequent to the adoption of Accounting Standards Codification ("ASC") 842, the Company will continue to recognize, on a discounted basis, its minimum commitments under noncancelable operating leases on its consolidated balance sheets. ASC 842 also provides practical expedients for an entity’s ongoing accounting. The Company has elected the short-term lease recognition exemption for all leases that qualify. Accordingly, the Company will not recognize right-of-use assets or lease liabilities for qualifying leases, including existing short-term leases in effect at the transition date, and will recognize those payments on the consolidated statements of operations on a straight-line basis over the lease term. Additionally, the Company has elected the practical expedient to not separate lease and non-lease components for all of its leases. See Note 4, Lease commitments, for additional disclosures. In January 2016, FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses, and additional changes, modifications, clarifications or interpretations thereafter, which require a reporting entity to estimate credit losses on certain types of financial instruments, and present assets held at amortized cost and available-for-sale debt securities at the amount expected to be collected. The new guidance is effective for annual and interim periods beginning after December 15, 2019, and early adoption is permitted. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements.
Revenue recognition	Revenue is recognized when control of goods or services is transferred to customers, in amounts that reflect the consideration the Company expects to be entitled to in exchange for those goods or services. The Company's performance obligation is typically to (a) deliver data records, based on predefined qualifying characteristics specified by the customer or (b) generate conversions, based on predefined user actions (for example, a click, a registration or the installation of an app) and subject to certain qualifying characteristics specified by the customer. The Company applies the practical expedient related to the review of a portfolio of contracts in reviewing the terms of customer contracts as one collective group, rather than by individual contract. Based on historical knowledge of the contracts contained in this portfolio and the similar nature and characteristics of the customers, the Company has concluded the financial statement effects are not materially different than accounting for revenue on a contract-by-contract basis. Revenue is recognized upon satisfaction of the associated performance obligations. The Company's customers simultaneously receive and consume the benefits provided as the Company satisfies its performance obligations. Furthermore, the Company elected the "right to invoice" practical expedient available within ASC 606-10-55-18 as the measure of progress, since the Company has a right to payment from a customer in an amount that corresponds directly with the value of the performance completed to date. The Company's revenue arrangements do not contain significant financing components. The Company has further concluded that revenue does not require disaggregation. If a customer pays consideration before the Company's performance obligations are satisfied, such amounts are classified as deferred revenue. As of March 31, 2019 and December 31, 2018, the balance of deferred revenue was $674 and $444, respectively. The majority of the deferred revenue balance as of December 31, 2018 was recognized into revenue during the first quarter of 2019. If there is a delay between the period in which revenue is recognized and when customer invoices are issued, revenue is recognized and related amounts are recorded as unbilled revenue in accounts receivable on the condensed consolidated balance sheets. As of March 31, 2019 and December 31, 2018, unbilled revenue included in accounts receivable totaled $23,413 and $25,545, respectively. In line with industry practice, the unbilled revenue balance is recorded based on the Company's internally-tracked conversions, net of estimated variances between this amount and the amount tracked and subsequently confirmed by customers. The majority of invoices included within the unbilled revenue balance are issued within the month directly following the period of service. Historical estimates related to unbilled revenue are not materially different from actual revenue billed. Sales commissions are recorded at the time revenue is recognized and recorded in sales and marketing expenses. The Company has elected to utilize a practical expedient to expense incremental costs incurred related to obtaining a contract. In addition, the Company elected the practical expedient to not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which revenue is recognized at the amount to which the Company has the right to invoice for services performed.