Overview and Basis of Presentation	3 Months Ended
Mar. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Overview and Basis of Presentation	Note 1. Overview and Basis of Presentation Company and Background Zendesk was founded in Denmark in 2007 and reincorporated in Delaware in April 2009. Our mission is to help organizations and their customers build better relationships. We are a software development company that provides a SaaS customer service platform that enables our customers to provide tailored support through multiple channels, establish effective self-service support resources, proactively serve customers through customer engagement capabilities, integrate with other applications, and consolidate and analyze data from customer interactions. We also provide SaaS live chat software that can be utilized independently to facilitate proactive communications between organizations and their customers or integrated easily into our platform. In October 2015, we completed the acquisition of We Are Cloud SAS, or WAC, the maker of BIME Analytics software. With the acquisition, we added technology that we anticipate will allow our customers to understand the ever-increasing diversity of data about their end customers. Over time, we expect this analytics software to become a core technology within our customer service platform, enabling us to further integrate data analytics capabilities across our products. We also expect to continue to sell our analytics software on a standalone basis. References to Zendesk, the “Company”, “our”, or “we” in these notes refer to Zendesk, Inc. and its subsidiaries on a consolidated basis. Basis of Presentation These unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or 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. Therefore, these condensed consolidated financial statements 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, 2015, filed on February 26, 2016. There have been no changes to our significant accounting policies described in the Annual Report on Form 10-K that have had a material impact on our condensed consolidated financial statements and related notes. The consolidated balance sheet as of December 31, 2015 included herein was derived from the audited financial statements as of that date. The unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, our comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full year ending December 31, 2016. Follow-On Public Offering In March 2015, we completed a follow-on public offering, in which we issued 8.8 million shares of our common stock at a public offering price of $22.75 per share. We received net proceeds of $190.1 million after deducting underwriting discounts and commissions of $8.7 million and other offering expenses of $0.9 million. Use of Estimates The preparation of consolidated 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 disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenue and expenses during the reported periods. Significant items subject to such estimates and assumptions include the fair value of share-based awards, acquired intangible assets and goodwill, unrecognized tax benefits, the useful lives of acquired intangible assets and property and equipment, and the capitalization and estimated useful life of our capitalized internal-use software. These estimates are based on information available as of the date of the financial statements; therefore, actual results could differ from those estimates. Concentrations of Risk As of March 31, 2016, no customers represented 10% or greater of our total accounts receivable balance. There were no customers that individually exceeded 10% of our revenue during the three months ended March 31, 2016 or 2015. Recently Issued and Adopted Accounting Pronouncements In May 2014, the FASB issued new revenue guidance that provides principles for recognizing revenue to which an entity expects to be entitled for the transfer of promised goods or services to customers. In August 2015, the FASB deferred the effective date of adoption by one year. As currently issued and amended, the new guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, though early adoption is permitted for annual reporting periods beginning after December 15, 2016. The amendment may be applied retrospectively to each prior period presented, or with the cumulative effect recognized as of the date of initial adoption. We have not yet selected a transition method and continue to evaluate the effect of the standard on our consolidated financial statements, including revenue and commissions. In September 2015, the FASB issued ASU 2015-16 “Simplifying the Accounting for Measurement-Period Adjustments,” which requires that an acquirer in a business combination recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The new standard is required to be applied prospectively. We adopted this guidance in the first quarter of 2016. The adoption of this standard did not have a material impact on our consolidated financial statements. In February 2016, the FASB issued ASU 2016-02 regarding ASC Topic 842 "Leases." This new standard requires lessees to recognize most leases on their balance sheets as lease liabilities with corresponding right-of-use assets and eliminates certain real estate-specific provisions. The new guidance is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements. In March 2016, the FASB issued ASU 2016-09 regarding Topic 718 "Compensation - Stock Compensation." This amendment changes certain aspects of accounting for share-based compensation to employees, including the recognition of income tax effects of awards when the awards vest or are settled, requirements on net share settlement to cover tax withholding, and accounting for forfeitures. The new guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.

Note 1. Overview and Basis of Presentation

Company and Background

Zendesk was founded in Denmark in 2007 and reincorporated in Delaware in April 2009.

Our mission is to help organizations and their customers build better relationships. We are a software development company that provides a SaaS customer service platform that enables our customers to provide tailored support through multiple channels, establish effective self-service support resources, proactively serve customers through customer engagement capabilities, integrate with other applications, and consolidate and analyze data from customer interactions. We also provide SaaS live chat software that can be utilized independently to facilitate proactive communications between organizations and their customers or integrated easily into our platform.

In October 2015, we completed the acquisition of We Are Cloud SAS, or WAC, the maker of BIME Analytics software. With the acquisition, we added technology that we anticipate will allow our customers to understand the ever-increasing diversity of data about their end customers. Over time, we expect this analytics software to become a core technology within our customer service platform, enabling us to further integrate data analytics capabilities across our products. We also expect to continue to sell our analytics software on a standalone basis.

References to Zendesk, the “Company”, “our”, or “we” in these notes refer to Zendesk, Inc. and its subsidiaries on a consolidated basis.

Basis of Presentation

These unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or 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. Therefore, these condensed consolidated financial statements 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, 2015, filed on February 26, 2016. There have been no changes to our significant accounting policies described in the Annual Report on Form 10-K that have had a material impact on our condensed consolidated financial statements and related notes.

The consolidated balance sheet as of December 31, 2015 included herein was derived from the audited financial statements as of that date. The unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, our comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full year ending December 31, 2016.

Follow-On Public Offering

In March 2015, we completed a follow-on public offering, in which we issued 8.8 million shares of our common stock at a public offering price of $22.75 per share. We received net proceeds of $190.1 million after deducting underwriting discounts and commissions of $8.7 million and other offering expenses of $0.9 million.

Use of Estimates

The preparation of consolidated 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 disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenue and expenses during the reported periods.

Significant items subject to such estimates and assumptions include the fair value of share-based awards, acquired intangible assets and goodwill, unrecognized tax benefits, the useful lives of acquired intangible assets and property and equipment, and the capitalization and estimated useful life of our capitalized internal-use software.

These estimates are based on information available as of the date of the financial statements; therefore, actual results could differ from those estimates.

Concentrations of Risk

As of March 31, 2016, no customers represented 10% or greater of our total accounts receivable balance. There were no customers that individually exceeded 10% of our revenue during the three months ended March 31, 2016 or 2015.

Recently Issued and Adopted Accounting Pronouncements

In May 2014, the FASB issued new revenue guidance that provides principles for recognizing revenue to which an entity expects to be entitled for the transfer of promised goods or services to customers. In August 2015, the FASB deferred the effective date of adoption by one year. As currently issued and amended, the new guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, though early adoption is permitted for annual reporting periods beginning after December 15, 2016. The amendment may be applied retrospectively to each prior period presented, or with the cumulative effect recognized as of the date of initial adoption. We have not yet selected a transition method and continue to evaluate the effect of the standard on our consolidated financial statements, including revenue and commissions.

In September 2015, the FASB issued ASU 2015-16 “Simplifying the Accounting for Measurement-Period Adjustments,” which requires that an acquirer in a business combination recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The new standard is required to be applied prospectively. We adopted this guidance in the first quarter of 2016. The adoption of this standard did not have a material impact on our consolidated financial statements.

In February 2016, the FASB issued ASU 2016-02 regarding ASC Topic 842 "Leases." This new standard requires lessees to recognize most leases on their balance sheets as lease liabilities with corresponding right-of-use assets and eliminates certain real estate-specific provisions. The new guidance is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.

In March 2016, the FASB issued ASU 2016-09 regarding Topic 718 "Compensation - Stock Compensation." This amendment changes certain aspects of accounting for share-based compensation to employees, including the recognition of income tax effects of awards when the awards vest or are settled, requirements on net share settlement to cover tax withholding, and accounting for forfeitures. The new guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.