Overview and Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2013
Accounting Policies [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”) develops, markets, and operates online social games as live services played over the Internet and on social networking sites and mobile platforms. We generate revenue through the in-game sale of virtual goods and through advertising. 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 Canada, Asia 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. *Accounting Policy Updates* 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, 2012 (the “Annual Report”). In June 2013, the Financial Accounting Standards Board ratified Emerging Issues Task Force (EITF) Issue 13-C, “Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists” which concludes an unrecognized tax benefit should be presented as a reduction of a deferred tax asset when settlement in this manner is available under the tax law. The Company will adopt this amendment in the first quarter of 2014. We do not expect our adoption of this standard to have a material impact on our financial statements. In 2013, we made additions to our accounting policies for stock based expense and business combinations, and updated our revenue recognition policy as it relates to our net accounting policy for online game revenue generated on Facebook, as more fully set forth below: Stock Based Expense For Zynga restricted stock units (“ZSUs”) granted prior to our initial public offering, and awards subject to a performance condition, we recognize stock-based compensation expense using the accelerated attribution method, net of estimated forfeitures, in which compensation cost for each vesting tranche in an award is recognized ratably from the service inception date to the vesting date for that tranche. For ZSUs granted after the initial public offering, which are only, or will be only, subject to a service condition, we recognize stock-based expense on a ratable basis over the requisite service period for the entire award. Business Combinations In line with our growth strategy, we have completed acquisitions to expand our social games and mobile offerings, obtain employee talent, and expand into new markets. We account for acquisitions of entities that include inputs and processes and have the ability to create outputs as business combinations. We allocate the purchase price of the acquisition, which includes the estimated acquisition date fair value of contingent consideration, to the tangible assets, liabilities and identifiable intangible assets acquired based on their estimated fair values. The excess of the purchase price over those fair values is recorded as goodwill. Determining the fair value of such items requires judgment, including estimating future cash flows or estimating the cost to recreate an acquired asset. If actual results are lower than estimates, we could be required to record impairment charges in the future. Acquired intangible assets are amortized over their estimated useful lives. Intangible assets with indefinite lives are not amortized but rather tested for impairment annually, or more frequently if circumstances exist which indicate an impairment may exist. Acquisition-related expenses and restructuring costs are expensed as incurred. During the one-year period beginning with the acquisition date, we may record certain purchase accounting adjustments related to the fair value of assets acquired and liabilities assumed against goodwill. After the final determination of the fair value of assets acquired or liabilities assumed, any subsequent adjustments are recorded to our consolidated statements of operations. We record changes in the fair value of contingent consideration liabilities within operating expenses in our consolidated statement of operations each reporting period. Revenue Recognition (Online Game) From July 2010 through the third quarter of 2013, Facebook’s proprietary virtual currency, Facebook Credits, was the primary in-game payment method for our games played on the Facebook platform. Under the terms of our agreement with Facebook, Facebook set the price our players pay for Facebook Credits and collected the funds from the sale of Facebook Credits. Facebook’s stated face value of a Facebook Credit was $0.10. For each Facebook Credit purchased by our players and redeemed in our games, Facebook remitted to us $0.07, which is the amount we recognized as revenue. Accordingly, we recognized revenue net of the amounts retained by Facebook related to Facebook Credits transactions because we did not set the pricing of Facebook Credits sold to the players of our games on Facebook. In July 2013, Facebook began to transition payments made on the Facebook platform from Facebook Credits to Facebook’s local currency-based payments program. This transition is ongoing and is expected to be completed in the fourth quarter of 2013. Under the terms of our agreement, Facebook remits to us 70% of the price we request to be charged to the game player for each transaction. We recognize revenue net of the amounts retained by Facebook related to Facebook local currency-based payments because Facebook may choose to alter our recommended price, for example by offering a discount or other incentives to players playing on their platform. Additionally we do not receive information from Facebook indicating the amount of such discounts offered to our paying players or regarding the actual cash paid by our players to Facebook. Accordingly, we are unable to determine the gross amount paid by our players to Facebook. *Unaudited Interim Financial Information* The accompanying interim consolidated balance sheet as of September 30, 2013, the interim consolidated statements of operations and, the interim consolidated statements of comprehensive income (loss) for the three and nine ended September 30, 2013 and 2012, and the interim consolidated statements of cash flows for the three and nine months ended September 30, 2013 and 2012 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 have been prepared on the same basis as the audited consolidated financial statements and 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 and nine months ended September 30, 2013 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.

1. Overview and Summary of Significant Accounting Policies

Organization and Description of Business

Zynga Inc. (“Zynga,” “we” or “the Company”) develops, markets, and operates online social games as live services played over the Internet and on social networking sites and mobile platforms. We generate revenue through the in-game sale of virtual goods and through advertising. 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 Canada, Asia 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.

Accounting Policy Updates

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, 2012 (the “Annual Report”).

In June 2013, the Financial Accounting Standards Board ratified Emerging Issues Task Force (EITF) Issue 13-C, “Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists” which concludes an unrecognized tax benefit should be presented as a reduction of a deferred tax asset when settlement in this manner is available under the tax law. The Company will adopt this amendment in the first quarter of 2014. We do not expect our adoption of this standard to have a material impact on our financial statements.

In 2013, we made additions to our accounting policies for stock based expense and business combinations, and updated our revenue recognition policy as it relates to our net accounting policy for online game revenue generated on Facebook, as more fully set forth below:

Stock Based Expense

For Zynga restricted stock units (“ZSUs”) granted prior to our initial public offering, and awards subject to a performance condition, we recognize stock-based compensation expense using the accelerated attribution method, net of estimated forfeitures, in which compensation cost for each vesting tranche in an award is recognized ratably from the service inception date to the vesting date for that tranche. For ZSUs granted after the initial public offering, which are only, or will be only, subject to a service condition, we recognize stock-based expense on a ratable basis over the requisite service period for the entire award.

Business Combinations

In line with our growth strategy, we have completed acquisitions to expand our social games and mobile offerings, obtain employee talent, and expand into new markets. We account for acquisitions of entities that include inputs and processes and have the ability to create outputs as business combinations. We allocate the purchase price of the acquisition, which includes the estimated acquisition date fair value of contingent consideration, to the tangible assets, liabilities and identifiable intangible assets acquired based on their estimated fair values. The excess of the purchase price over those fair values is recorded as goodwill. Determining the fair value of such items requires judgment, including estimating future cash flows or estimating the cost to recreate an acquired asset. If actual results are lower than estimates, we could be required to record impairment charges in the future. Acquired intangible assets are amortized over their estimated useful lives. Intangible assets with indefinite lives are not amortized but rather tested for impairment annually, or more frequently if circumstances exist which indicate an impairment may exist.

Acquisition-related expenses and restructuring costs are expensed as incurred. During the one-year period beginning with the acquisition date, we may record certain purchase accounting adjustments related to the fair value of assets acquired and liabilities assumed against goodwill. After the final determination of the fair value of assets acquired or liabilities assumed, any subsequent adjustments are recorded to our consolidated statements of operations. We record changes in the fair value of contingent consideration liabilities within operating expenses in our consolidated statement of operations each reporting period.

Revenue Recognition (Online Game)

From July 2010 through the third quarter of 2013, Facebook’s proprietary virtual currency, Facebook Credits, was the primary in-game payment method for our games played on the Facebook platform. Under the terms of our agreement with Facebook, Facebook set the price our players pay for Facebook Credits and collected the funds from the sale of Facebook Credits. Facebook’s stated face value of a Facebook Credit was $0.10. For each Facebook Credit purchased by our players and redeemed in our games, Facebook remitted to us $0.07, which is the amount we recognized as revenue. Accordingly, we recognized revenue net of the amounts retained by Facebook related to Facebook Credits transactions because we did not set the pricing of Facebook Credits sold to the players of our games on Facebook.

In July 2013, Facebook began to transition payments made on the Facebook platform from Facebook Credits to Facebook’s local currency-based payments program. This transition is ongoing and is expected to be completed in the fourth quarter of 2013. Under the terms of our agreement, Facebook remits to us 70% of the price we request to be charged to the game player for each transaction. We recognize revenue net of the amounts retained by Facebook related to Facebook local currency-based payments because Facebook may choose to alter our recommended price, for example by offering a discount or other incentives to players playing on their platform. Additionally we do not receive information from Facebook indicating the amount of such discounts offered to our paying players or regarding the actual cash paid by our players to Facebook. Accordingly, we are unable to determine the gross amount paid by our players to Facebook.

Unaudited Interim Financial Information

The accompanying interim consolidated balance sheet as of September 30, 2013, the interim consolidated statements of operations and, the interim consolidated statements of comprehensive income (loss) for the three and nine ended September 30, 2013 and 2012, and the interim consolidated statements of cash flows for the three and nine months ended September 30, 2013 and 2012 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 have been prepared on the same basis as the audited consolidated financial statements and 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 and nine months ended September 30, 2013 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.