Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements include Impinj, Inc. and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. These condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States, or GAAP, and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and accompanying notes as of and for the year ended December 31, 2015 included our prospectus, or the Prospectus, filed with the SEC on pursuant to Rule 424(b) under the Securities Act of 1933 on July 21, 2016. The condensed consolidated balance sheet as of December 31, 2015, included herein, was derived from the audited financial statements of Impinj, Inc. The unaudited condensed consolidated interim financial statements, in the opinion of management, reflect all adjustments, consisting of normal recurring adjustments, necessary to state fairly our financial position as of June 30, 2016, our results of operations for the three and six month periods ended June 30, 2016 and 2015, and our cash flows for the six month periods ended June 30, 2016 and 2015. Operating results for the three and six months ended June 30, 2016 are not necessarily indicative of the results to be expected for the year ended December 31, 2016 or for any other future period.
Reclassifications	Reclassifications In the consolidated statements of operations, certain prior year amounts have been reclassified to conform to the current year presentation. During the three and six months ended June 30, 2015, respectively, cost of product revenue increased $24,000 and $46,000, research and development expenses increased $106,000 and $209,000, sales and marketing expenses increased $44,000 and $86,000 and general and administrative expenses decreased $174,000 and $341,000. There was no change to the net income as a result of the reclassification.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and the related disclosures at the date of the financial statements, as well as the reported amounts of revenue and expenses during the periods presented. On an ongoing basis, we evaluate our estimates, including those related to revenue recognition, reserve for returns, collectability of accounts receivable, estimated costs to complete development contracts, warranty obligations, deferred revenue, inventory excess and obsolescence, depreciable lives of fixed assets, the determination of the fair value of stock awards and warrants and accrued liabilities, compensation and employee related benefits. To the extent there are material differences between these estimates, judgments, or assumptions and actual results, our financial statements will be affected.
Certain Significant Risks and Uncertainties	Certain Significant Risks and Uncertainties Inherent in our business are various risks and uncertainties, including that we are developing advanced technologies and new applications in a rapidly changing industry. These risks include the failure to develop and extend our products and the rejection of our products by consumers, as well as other risks and uncertainties. If we do not successfully implement our business plan, certain assets may not be recoverable, certain liabilities may not be paid and investments in our capital stock may not be recoverable. Our success depends upon the acceptance of our technology, development of sales and distribution channels and our ability to generate significant revenue from the use of our technology.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs, consisting of legal, accounting and other fees and costs related to our initial public offering, are capitalized. The deferred offering costs will be offset against proceeds upon the closing of the offering. These costs have been deferred through the completion of the initial public offering and on the closing date of July 26, 2016, will be reclassified to additional paid-in capital as a reduction of the proceeds. There were $1.5 million of capitalized deferred offering costs as of June 30, 2016 and $637,000 of capitalized deferred offering costs as of December 31, 2015.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In March 2016, the Financial Accounting Standards Board, or FASB, issued guidance on several aspects of the accounting for share-based payment transactions, including the income tax consequences, impact of forfeitures, classification of awards as either equity or liabilities and classification on the statement of cash flows. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, and early adoption is permitted. We have not yet determined our approach to adoption or the impact the adoption of this guidance will have on our financial position, results of operations or cash flows. In February 2016, the FASB issued guidance on leases. This standard requires the recognition of a right-of-use asset and lease liability on the balance sheet for all leases. This standard also requires more detailed disclosures to enable users of financial statements to understand the amount, timing, and uncertainty of cash flows arising from leases. This guidance is effective for interim and annual reporting periods beginning after December 15, 2018 and should be applied through a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, and early adoption is permitted. We expect to adopt this guidance on January 1, 2019. We believe adoption of this standard will have a significant impact on our Consolidated Balance Sheets. Although we have not completed our assessment, we do not expect the adoption to change the recognition, measurement or presentation of lease expenses within the Consolidated Statements of Operations and Cash Flows. In January 2016, the FASB issued guidance on the recognition and measurement of financial instruments. This standard requires equity investments, except those accounted for under the equity method of accounting or those that result in consolidation of the investee, to be measured at fair value with changes in fair value recognized in net income. This standard also requires the separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017, early adoption is permitted, and the guidance must be applied prospectively to equity investments that exist as of the adoption date. We expect to adopt this guidance on January 1, 2018. We have not yet determined our approach to adoption or the impact the adoption of this guidance will have on our financial position, results of operations or cash flows. In November 2015, the FASB issued guidance on the balance sheet classification of deferred taxes. This standard requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. This guidance is effective for interim and annual reporting periods beginning after December 15, 2016, and early adoption is permitted. We adopted this guidance as of January 1, 2016. The adoption of this guidance has no impact on our financial position, results of operations or cash flows. In July 2015, the FASB issued guidance on the measurement of inventory. The amendments require the measurement of inventory at the lower of cost or net realizable value; where net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. This guidance is effective for interim and annual reporting periods beginning after December 31, 2016, and early adoption is permitted. We expect to adopt this guidance on January 1, 2017. We have not yet determined our approach to adoption or the impact the adoption of this guidance will have on our financial position, results of operations or cash flows. In August 2014, the FASB issued guidance on the disclosure of uncertainties about an entity’s ability to continue as a going concern. This standard provides guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. The guidance is effective for annual reporting periods ending after December 15, 2016, and early adoption is permitted. We expect to adopt this guidance for the year ending December 31, 2016. We do not expect the adoption of this guidance to have any impact on our financial position, results of operations or cash flows. In May 2014, the FASB issued guidance on revenue recognition. This guidance provides that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This guidance also requires more detailed disclosures to enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The original effective date of this guidance was for interim and annual reporting periods beginning after December 15, 2016, early adoption is not permitted, and the guidance must be applied retrospectively or modified retrospectively. In July 2015, the FASB approved an optional one-year deferral of the effective date. As a result, we expect to adopt this guidance on January 1, 2018. In 2016, the FASB issued final amendments to clarify the implementation guidance for principal versus agent considerations, identifying performance obligations and the accounting for licenses of intellectual property. We have not yet determined our approach to adoption or the impact the adoption of this guidance will have on our financial position, results of operations or cash flows, if any.