Overview and Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Overview and Summary of Significant Accounting Policies	1. Overview and Summary of Significant Accounting Policies Organization and Description of Business Zynga Inc. (“Zynga,” “we” or the “Company”) is a leading provider of social game services. We develop, market and operate social games as live services played on mobile platforms such as iOS and Android and social networking sites such as Facebook. Generally, all of our games are free to play, and we generate revenue through the in-game sale of virtual goods and advertising services. Our operations are headquartered in San Francisco, California, and we have several operating locations in the U.S. as well as various international office locations in North America, India and Europe. We completed our initial public offering in December 2011 and our Class A common stock is listed on the NASDAQ Global Select Market under the symbol “ZNGA.” Basis of Presentation and Consolidation The accompanying consolidated financial statements are presented in accordance with United States generally accepted accounting principles (“U.S. GAAP”). The consolidated financial statements include the operations of us and our wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in the consolidation. The accompanying interim consolidated financial statements and these related notes should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2016. Unaudited Interim Financial Information The accompanying interim consolidated balance sheet as of March 31, 2017, the interim consolidated statements of operations, the interim consolidated statements of comprehensive income (loss) for the three months ended March 31, 2017 and 2016, the interim consolidated statements of cash flows for the three months ended March 31, 2017 and 2016 and the related footnote disclosures are unaudited. These unaudited consolidated interim financial statements have been prepared in accordance with U.S. GAAP. In management’s opinion, the unaudited consolidated interim financial statements include all adjustments of a normal recurring nature necessary for the fair presentation of the Company’s statement of financial position and operating results for the periods presented. The results for the three months ended March 31, 2017 are not necessarily indicative of the results expected for the full fiscal year or any other future period. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts in the consolidated financial statements and notes thereto. Significant estimates and assumptions reflected in the financial statements include, but are not limited to, the estimated lives of virtual goods that we use for revenue recognition, useful lives of property and equipment and intangible assets, accrued liabilities, income taxes, accounting for business combinations, stock-based expense and evaluation of goodwill, intangible assets, and long-lived assets for impairment. Actual results could differ materially from those estimates. In the first quarter of 2017, there were no changes in our estimated average life of durable virtual goods or discontinued games that required adjusting the recognition period of deferred revenue generated in prior periods. In the first quarter of 2016, changes in our estimated average life of durable virtual goods for various games resulted in an increase in revenue and income from operations of $2.6 million, which was the result of adjusting the remaining recognition period of deferred revenue generated in prior periods at the time of a change in estimate. We also recognized $1.3 million of revenue and income from operations in the first quarter of 2016 due to changes in our estimated average life of durable virtual goods for games that have been discontinued as there is no further service obligation after the closure of these games. These changes in estimates had a $0.01 per share impact on our reported earnings per share in the first quarter of 2016. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers (Topic 606),” which requires revenue to be recognized when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. ASU 2014-09 supersedes the existing revenue recognition guidance in “Revenue Recognition (Topic 605)” and is effective for interim and annual reporting periods beginning after December 15, 2017. The standard permits the use of either a full retrospective or modified retrospective (cumulative effect) transition method and we will apply the modified retrospective approach when we adopt the standard in the first quarter of 2018. Based on our initial assessment, the impact of the application of the new standard will likely result in a change in timing of our revenue recognition for software licensing related to NaturalMotion technology, which is currently recognized as revenue over time, rather than at a point in time. Under the new standard, we will be required to estimate the standalone selling price of software licenses separate from any associated maintenance services and recognize revenue for the license when control is transferred. While software licensing related to NaturalMotion is not material to our revenue, this will likely result in an acceleration in revenue recognition compared to the current method. Another key change in the standard that impacts our revenue recognition relates to the explicit collectability threshold a contract must meet before revenue can be recognized. For certain advertising arrangements where we have assessed that collectability is not reasonably assured due to unfavorable payment terms or a history of slow collections, the current practice is to defer revenue recognition until payment is received. However, under the new standard, we will be required to make an assessment of collectability at the inception of the contract and if deemed probable for collection, recognize revenue as advertisements are delivered, which will result in an acceleration in revenue recognition compared to the current method. While we are still completing our assessment for the population of advertisers under consideration, we do not expect this change to have a material impact on our revenue. We are currently in the process of evaluating other possible impacts on our consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842),” which requires a lessee to recognize assets and liabilities on the balance sheet for leases with lease terms greater than 12 months. For lessors, accounting for leases will remain substantially the same as in prior periods. The standard is effective in the first quarter of 2019 and early adoption is permitted. While the Company expects adoption of this new standard to increase reported assets and liabilities, we are currently in the process of evaluating the timing of adoption of ASU 2016-02 as well as the full impact on our consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, “Stock Compensation (Topic 718): Improvements to Employee Shared-Based Payment Accounting”, which simplifies and improves several aspects of the accounting for employee share-based payment transactions for public entities. The new guidance requires companies to record excess tax benefits and tax deficiencies as income tax benefit or expense in the statement of operations when the awards vest or are settled, eliminates the requirement to reclassify cash flows related to excess tax benefits from operating activities to financing activities on the statement of cash flows and provides the option to recognize share-based compensation expense with actual forfeitures recognized as they occur, rather than estimate expected forfeitures. We adopted the standard in the first quarter of 2017. Upon adoption, we recognized the previously unrecognized excess tax benefits using the modified retrospective transition method, which resulted in a cumulative-effect adjustment of $48.2 million to retained earnings (a reduction in the accumulated deficit). The previously unrecognized excess tax effects were recorded as a deferred tax asset, which was fully offset by a valuation allowance. Without the valuation allowance, our deferred tax asset would have increased by $97.3 million. We elected to apply the change in presentation of excess tax benefits as an operating activity in the statement of cash flow prospectively and thus no prior periods were adjusted. We also elected to account for forfeitures as they occur using the modified retrospective transition method, which resulted in a cumulative-effect adjustment of $3.9 million to retained earnings (an increase in the accumulated deficit). In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which provides guidance on specific issues related to how certain cash receipts and cash payments are classified in the statement of cash flows, with the objective of reducing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017 and early adoption is permitted. We will adopt the standard in the first quarter of 2018 and are currently in the process of evaluating the impact on our consolidated financial statements and related disclosures. In November 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash,” which requires companies to include amounts generally described as restricted cash and restricted cash equivalents in cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the statement of cash flows, with the objective of reducing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 31, 2017 and early adoption is permitted. We will adopt the standard in the first quarter of 2018 and are currently in the process of evaluating the impact on our consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU 2017-01, “Business Combinations (Topic 805) Clarifying the Definition of a Business,” which clarifies the definition of a business to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The standard is effective for interim and annual periods beginning after December 15, 2017 and early adoption is permitted. We will adopt the standard in the first quarter of 2018 and are currently in the process of evaluating the impact on our consolidated financial statements and related disclosures.

1. Overview and Summary of Significant Accounting Policies

Organization and Description of Business

Zynga Inc. (“Zynga,” “we” or the “Company”) is a leading provider of social game services. We develop, market and operate social games as live services played on mobile platforms such as iOS and Android and social networking sites such as Facebook. Generally, all of our games are free to play, and we generate revenue through the in-game sale of virtual goods and advertising services. Our operations are headquartered in San Francisco, California, and we have several operating locations in the U.S. as well as various international office locations in North America, India and Europe.

We completed our initial public offering in December 2011 and our Class A common stock is listed on the NASDAQ Global Select Market under the symbol “ZNGA.”

Basis of Presentation and Consolidation

The accompanying consolidated financial statements are presented in accordance with United States generally accepted accounting principles (“U.S. GAAP”). The consolidated financial statements include the operations of us and our wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in the consolidation.

The accompanying interim consolidated financial statements and these related notes should be read in conjunction with the consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2016.

Unaudited Interim Financial Information

The accompanying interim consolidated balance sheet as of March 31, 2017, the interim consolidated statements of operations, the interim consolidated statements of comprehensive income (loss) for the three months ended March 31, 2017 and 2016, the interim consolidated statements of cash flows for the three months ended March 31, 2017 and 2016 and the related footnote disclosures are unaudited. These unaudited consolidated interim financial statements have been prepared in accordance with U.S. GAAP. In management’s opinion, the unaudited consolidated interim financial statements include all adjustments of a normal recurring nature necessary for the fair presentation of the Company’s statement of financial position and operating results for the periods presented. The results for the three months ended March 31, 2017 are not necessarily indicative of the results expected for the full fiscal year or any other future period.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts in the consolidated financial statements and notes thereto. Significant estimates and assumptions reflected in the financial statements include, but are not limited to, the estimated lives of virtual goods that we use for revenue recognition, useful lives of property and equipment and intangible assets, accrued liabilities, income taxes, accounting for business combinations, stock-based expense and evaluation of goodwill, intangible assets, and long-lived assets for impairment. Actual results could differ materially from those estimates.

In the first quarter of 2017, there were no changes in our estimated average life of durable virtual goods or discontinued games that required adjusting the recognition period of deferred revenue generated in prior periods. In the first quarter of 2016, changes in our estimated average life of durable virtual goods for various games resulted in an increase in revenue and income from operations of $2.6 million, which was the result of adjusting the remaining recognition period of deferred revenue generated in prior periods at the time of a change in estimate. We also recognized $1.3 million of revenue and income from operations in the first quarter of 2016 due to changes in our estimated average life of durable virtual goods for games that have been discontinued as there is no further service obligation after the closure of these games. These changes in estimates had a $0.01 per share impact on our reported earnings per share in the first quarter of 2016.

Recent Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers (Topic 606),” which requires revenue to be recognized when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. ASU 2014-09 supersedes the existing revenue recognition guidance in “Revenue Recognition (Topic 605)” and is effective for interim and annual reporting periods beginning after December 15, 2017. The standard permits the use of either a full retrospective or modified retrospective (cumulative effect) transition method and we will apply the modified retrospective approach when we adopt the standard in the first quarter of 2018.

Based on our initial assessment, the impact of the application of the new standard will likely result in a change in timing of our revenue recognition for software licensing related to NaturalMotion technology, which is currently recognized as revenue over time, rather than at a point in time. Under the new standard, we will be required to estimate the standalone selling price of software licenses separate from any associated maintenance services and recognize revenue for the license when control is transferred. While software licensing related to NaturalMotion is not material to our revenue, this will likely result in an acceleration in revenue recognition compared to the current method. Another key change in the standard that impacts our revenue recognition relates to the explicit collectability threshold a contract must meet before revenue can be recognized. For certain advertising arrangements where we have assessed that collectability is not reasonably assured due to unfavorable payment terms or a history of slow collections, the current practice is to defer revenue recognition until payment is received. However, under the new standard, we will be required to make an assessment of collectability at the inception of the contract and if deemed probable for collection, recognize revenue as advertisements are delivered, which will result in an acceleration in revenue recognition compared to the current method. While we are still completing our assessment for the population of advertisers under consideration, we do not expect this change to have a material impact on our revenue. We are currently in the process of evaluating other possible impacts on our consolidated financial statements.

In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842),” which requires a lessee to recognize assets and liabilities on the balance sheet for leases with lease terms greater than 12 months. For lessors, accounting for leases will remain substantially the same as in prior periods. The standard is effective in the first quarter of 2019 and early adoption is permitted. While the Company expects adoption of this new standard to increase reported assets and liabilities, we are currently in the process of evaluating the timing of adoption of ASU 2016-02 as well as the full impact on our consolidated financial statements.

In March 2016, the FASB issued ASU 2016-09, “Stock Compensation (Topic 718): Improvements to Employee Shared-Based Payment Accounting”, which simplifies and improves several aspects of the accounting for employee share-based payment transactions for public entities. The new guidance requires companies to record excess tax benefits and tax deficiencies as income tax benefit or expense in the statement of operations when the awards vest or are settled, eliminates the requirement to reclassify cash flows related to excess tax benefits from operating activities to financing activities on the statement of cash flows and provides the option to recognize share-based compensation expense with actual forfeitures recognized as they occur, rather than estimate expected forfeitures. We adopted the standard in the first quarter of 2017. Upon adoption, we recognized the previously unrecognized excess tax benefits using the modified retrospective transition method, which resulted in a cumulative-effect adjustment of $48.2 million to retained earnings (a reduction in the accumulated deficit). The previously unrecognized excess tax effects were recorded as a deferred tax asset, which was fully offset by a valuation allowance. Without the valuation allowance, our deferred tax asset would have increased by $97.3 million. We elected to apply the change in presentation of excess tax benefits as an operating activity in the statement of cash flow prospectively and thus no prior periods were adjusted. We also elected to account for forfeitures as they occur using the modified retrospective transition method, which resulted in a cumulative-effect adjustment of $3.9 million to retained earnings (an increase in the accumulated deficit).

In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which provides guidance on specific issues related to how certain cash receipts and cash payments are classified in the statement of cash flows, with the objective of reducing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 15, 2017 and early adoption is permitted. We will adopt the standard in the first quarter of 2018 and are currently in the process of evaluating the impact on our consolidated financial statements and related disclosures.

In November 2016, the FASB issued ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash,” which requires companies to include amounts generally described as restricted cash and restricted cash equivalents in cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the statement of cash flows, with the objective of reducing diversity in practice. This guidance is effective for interim and annual reporting periods beginning after December 31, 2017 and early adoption is permitted. We will adopt the standard in the first quarter of 2018 and are currently in the process of evaluating the impact on our consolidated financial statements and related disclosures.

In January 2017, the FASB issued ASU 2017-01, “Business Combinations (Topic 805) Clarifying the Definition of a Business,” which clarifies the definition of a business to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The standard is effective for interim and annual periods beginning after December 15, 2017 and early adoption is permitted. We will adopt the standard in the first quarter of 2018 and are currently in the process of evaluating the impact on our consolidated financial statements and related disclosures.