| Significant Accounting Policies | Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles in the United States (U.S. GAAP) requires management to make estimates, judgments, and assumptions that affect the reported amounts of assets and liabilities; the disclosure of contingent liabilities at the date of the financial statements; and the reported amounts of revenues and expenses during the reporting periods. Significant estimates, assumptions, and judgments are used for, but not limited to: revenue recognition, recoverability of accounts receivable, restructuring charges, share-based compensation expense including estimated forfeitures, accounting for income taxes, useful lives assigned to long-lived assets for depreciation and amortization, impairment of goodwill and long-lived assets, the valuation of acquired intangible assets, the valuation of our convertible senior notes, internal-use software and website development costs, and operating lease right of use (ROU) assets and operating lease liabilities. We base our estimates on historical experience, knowledge of current business conditions, and various other factors we believe to be reasonable under the circumstances. These estimates are based on management’s knowledge about current events and expectations about actions we may undertake in the future. Actual results could differ from these estimates, and such differences could be material to our financial position and results of operations. Principles of Consolidation The consolidated financial statements include the accounts of Chegg and our wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The consolidated financial statements have been prepared in accordance with U.S. GAAP. Cash and Cash Equivalents and Restricted Cash We consider all highly liquid investments with an original maturity date of three months or less from the date of purchase to be cash equivalents. Our cash and cash equivalents consist of cash, money market accounts, and commercial paper at financial institutions, and are stated at cost, which approximates fair value. We classify certain restricted cash balances within other current assets and other assets on the accompanying consolidated balance sheets based upon the term of the remaining restrictions. Investments We hold investments in commercial paper, corporate securities, U.S. treasury securities, and agency bonds. We classify our investments as available-for-sale that are either short or long-term based on the nature of each security based on the contractual maturity of the investment when purchased. Our available-for-sale investments are carried at estimated fair value with any unrealized gains and losses, net of taxes, included in other comprehensive loss on our consolidated statements of stockholders’ equity. Unrealized losses are charged against other income, net when a decline in fair value is determined to be other-than-temporary. We did not record any such impairment charges in the periods presented. We determined realized gains or losses on the sale of investments on a specific identification method, and recorded such gains or losses as other income, net. For the years ended December 31, 2019 , 2018 and 2017 , the Company's gross realized gains and losses on investments were not significant. Accounts Receivable Accounts receivable are recorded at the invoiced amount and are non-interest bearing. We generally grant uncollateralized credit terms to our customers, which include textbook wholesalers and marketing services customers, and maintain an allowance for doubtful accounts to account for potentially uncollectible receivables. Allowance for Doubtful Accounts We assess the creditworthiness of our customers based on multiple sources of information, and analyze such factors as our historical bad debt experience, industry and geographic concentrations of credit risk, economic trends, and customer payment history. This assessment requires significant judgment. Because of this assessment, we maintain an allowance for doubtful accounts for estimated losses resulting from the inability of certain customers to make all of their required payments. In making this estimate, we analyze historical payment performance and current economic trends when evaluating the adequacy of the allowance for doubtful accounts. Accounts receivable are written off as a decrease to the allowance for doubtful accounts when all collection efforts have been exhausted and an account is deemed uncollectible. Concentration of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, and investments in highly liquid instruments in accordance with our investment policy. We place the majority of our cash and cash equivalents and restricted cash with financial institutions in the United States that we believe to be of high credit quality, and accordingly minimal credit risk exists with respect to these instruments. Certain of our cash balances held with a financial institution are in excess of Federal Deposit Insurance Corporation limits. Our investment portfolio consists of investments diversified among security types, industries and issuers. Our investments were held and managed by recognized financial institutions that followed our investment policy with the main objective of preserving capital and maintaining liquidity. Concentrations of credit risk with respect to accounts receivables exist to the full extent of amounts presented in the financial statements. We had one customer, in each year, that represented 11% of our net accounts receivable balance as of December 31, 2019 and 2018 . No customers represented over 10% of net revenues during the years ended December 31, 2019 , 2018 or 2017 . Property and Equipment Property and equipment are recorded at cost less accumulated depreciation and content amortization. Depreciation and content amortization are computed using the straight-line method over the following estimated useful lives of the assets: Classification Useful Life Computers and equipment 3 years Internal-use software and website development 3 years Furniture and fixtures 5 years Leasehold improvements Shorter of the remaining lease term or the estimated useful life of 5 years Content Shorter of the licensed content term or the estimated useful life of 5 years Depreciation and content amortization expense are generally classified within the corresponding cost of revenues and operating expenses categories in our consolidated statements of operations. Depreciation and content amortization expense during the years ended December 31, 2019 , 2018 , and 2017 were approximately $24.2 million , $16.8 million , and $13.8 million , respectively. The cost of maintenance and repairs is expensed as incurred. When assets are retired or otherwise disposed of, the cost and related accumulated depreciation and amortization are removed from their respective accounts, and any gain or loss on such sale or disposal is reflected in income (loss) from operations. Internal-Use Software and Website Development Costs We capitalize certain costs associated with software developed or obtained for internal use and website and application development. We capitalize costs when preliminary development efforts are successfully completed, management has authorized and committed project funding and it is probable that the project will be completed and the software will be used as intended. Such costs are amortized on a straight-line basis over a three year estimated useful life of the related asset. Costs incurred prior to meeting these criteria, together with costs incurred for training and maintenance, are expensed as incurred. Costs incurred for enhancements that are expected to result in additional material functionality are capitalized and amortized over the estimated useful life of the upgrades. Business Combinations We allocate the fair value of purchase consideration to the tangible assets acquired, liabilities assumed and intangible assets acquired through a business combination based on their estimated fair values. The excess of the fair value of purchase consideration over the fair values of these identifiable assets acquired and liabilities assumed is recorded as goodwill. Such valuations require management to make significant estimates and assumptions, especially with respect to intangible assets. Significant estimates in valuing certain intangible assets include, but are not limited to, future expected cash flows from acquired users, acquired technology, and trade names from a market participant perspective, useful lives and discount rates. Management’s estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. During the measurement period, which is not to exceed one year from the acquisition date, we may record adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. Upon the conclusion of the measurement period, any subsequent adjustments are recorded to earnings. Goodwill and Indefinite-Lived Intangible Asset Goodwill represents the excess of the fair value of purchase consideration paid over the estimated fair value of assets acquired and liabilities assumed in a business combination. Our indefinite-lived intangible asset represents the internships.com trade name. Goodwill and our indefinite-lived intangible asset are not amortized but rather tested for impairment at least annually on October 1, or more frequently if certain events or indicators of impairment occur between annual impairment tests. We first assess qualitative factors to determine whether it is necessary to perform the quantitative impairment test. In our qualitative assessment, we consider factors including economic conditions, industry and market conditions and developments, overall financial performance and other relevant entity-specific events in determining whether it is more likely than not that the fair value of our reporting unit is less than the carrying amount. We completed our annual impairment test on October 1st of 2019 and 2018 , each of which did not result in any impairment as our qualitative assessment did not indicate that it is more likely than not that the fair value of our reporting unit is less than the carrying amount. As of December 31, 2019 and 2018 , we had goodwill of $214.5 million and $149.5 million , respectively, and an indefinite lived intangible asset related to the internships.com trade name of $3.6 million . Acquired Intangible Assets and Other Long-Lived Assets Acquired intangible assets with finite useful lives, which include developed technology, content library, customer lists, trade names and non-compete agreements, are amortized over their estimated useful lives. We assess the impairment of acquired intangible assets and other long-lived assets when events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Leases We determine if an arrangement is a lease at inception. Operating leases are included in operating lease ROU assets and operating lease liabilities within current liabilities and long-term liabilities on our consolidated balance sheet. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Our leases do not provide an implicit rate and therefore we use our incremental borrowing rate based on the information available at commencement date in determining the present value of future minimum lease payments. Our incremental borrowing rate is estimated based on the estimated rate incurred to borrow, on a collateralized basis over a similar term as our leases, an amount equal to the lease payments in a similar economic environment. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise such options. We do not record leases on our consolidated balance sheet with a term of one year or less. We do not separate lease and non-lease components but rather account for each separate component as a single lease component for all underlying classes of assets. Some of our leases include payments that are dependent on an index, such as the Consumer Price Index (CPI), and our minimum lease payments include payments based on the index at inception with any future changes in such indices recognized as an expense in the period of change. Where leases contain escalation clauses, rent abatements, or concessions, such as rent holidays and landlord or tenant incentives or allowances, we apply them in the determination of straight-line operating lease cost over the lease term. Strategic Investments We have entered into strategic investments that are accounted for under the cost method and included in other assets on our consolidated balance sheets. We assess our strategic investments for impairment whenever events or changes in circumstances indicate that the strategic investments may be impaired. The factors we consider in our evaluation include, but are not limited to, a significant deterioration in the earnings performance or business prospects of the investee or factors that raise significant concerns about the investee’s ability to continue as a going concern, such as negative cash flows from operations or working capital deficiencies. Additionally, starting in 2018 as a result of our adoption of Accounting Standards Update (ASU) 2016-01, we consider whether there have been any observable price changes in orderly transactions for identical or similar investments. During the years ended December 31, 2019 , 2018 , and 2017 , we did not record any impairment charges in our strategic investments. There is a potential for charges in future periods if we determine that our strategic investments are impaired. During the years ended December 31, 2019 and 2018 , there were no observable price changes in orderly transactions for the identical or similar investments of the same issuers. Convertible Senior Notes, net In March 2019, we issued $700 million in aggregate principal amount of 0.125% convertible senior notes due in 2025 (2025 notes) and in April 2019, the initial purchasers fully exercised their option to purchase $100 million of additional 2025 notes for aggregate total gross proceeds of $800 million . In April 2018, we issued $345 million in aggregate principal amount of 0.25% convertible senior notes due in 2023 (2023 notes). Collectively, the 2025 notes and the 2023 notes are referred to as the “notes.” In accounting for their issuance, we separated the notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of similar liabilities that do not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the carrying amount of the liability component from the par value of the notes. The difference represents the debt discount, recorded as a reduction of the convertible senior notes on our consolidated balance sheet, and is amortized to interest expense over the term of the notes using the effective interest rate method. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. In accounting for the issuance costs related to the notes, we allocated the total amount of issuance costs incurred to liability and equity components based on their relative values. Issuance costs attributable to the liability component are being amortized on a straight-line basis, which approximates the effective interest rate method, to interest expense over the term of the notes. The issuance costs attributable to the equity component are recorded as a reduction of the equity component within additional paid-in capital. Revenue Recognition and Deferred Revenue We recognize revenues from our Chegg Services and Required Materials offerings when control of the goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. We determine revenue recognition through the following steps: • Identification of the contract, or contracts, with a customer • Identification of the performance obligations in the contract • Determination of the transaction price • Allocation of the transaction price to the performance obligations in the contract • Recognition of revenue when, or as, we satisfy a performance obligation We generate revenues from our Chegg Services product line primarily through Chegg Study, Chegg Writing, Chegg Tutors, Chegg Math Solver, and Thinkful . Chegg Services are offered to students primarily through weekly or monthly subscriptions, and we recognize revenues ratably over the respective subscription period. Revenues from Thinkful, our skills-based learning platform, are recognized either ratably over the term of the course, generally six months, or upon completion of the lessons, depending on the instruction type of the course. Revenues from our Required Materials product line includes a revenue share, upon fulfillment, on the total transactional amount of a rental and sale transaction for print textbooks . The revenue share on the rental and sale of print textbooks is recognized immediately when a book ships to the student. Shipping and handling activities are performed after we recognize revenues and we have elected to account for them as activities to fulfill a print textbook rental or sale order. Revenues from the rental of eTextbooks is recognized ratably over the contractual period, generally two to five months. Revenues from the sale of eTextbooks is recognized immediately when the eTextbook sale occurs. Revenues are presented net of sales tax collected from customers to be remitted to governmental authorities and net of allowances for estimated cancellations and customer returns, which are based on historical data. Customer refunds from cancellations and returns are recorded as a reduction to revenues. Some of our customer arrangements include multiple performance obligations. We have determined these performance obligations qualify as distinct performance obligations, as the customer can benefit from the service on its own or together with other resources that are readily available to the customer and our promise to transfer the service is separately identifiable from other promises in the contract. For these arrangements that contain multiple performance obligations, we allocate the transaction price based on the relative standalone selling price method by comparing the standalone selling price (SSP) of each distinct performance obligation to the total value of the contract. We determine the SSP based on our historical pricing and discounting practices for the distinct performance obligation when sold separately. If the SSP is not directly observable, we estimate the SSP by considering information such as market conditions, and information about the customer. Additionally, we limit the amount of revenues recognized for delivered promises to the amount that is not contingent on future delivery of services or other future performance obligations. Our agreements with print textbook partners may include an amount of variable consideration in addition to a fixed revenue share that we earn. This variable consideration can either increase or decrease the total transaction price depending on the nature of the variable consideration. We estimate the amount of variable consideration that we will earn at the inception of the contract, adjusted during each period, and include an estimated amount each period. For sales of third-party products, we evaluate whether we are acting as a principal or an agent, and therefore would record the gross sales amount as revenues and related costs or the net amount earned as a revenue share from the sale of third- party products. Our determination is based on our evaluation of whether we control the specified goods or services prior to transferring them to the customer. In relation to print textbook rental and sale agreements with our partners, we recognize revenues on a net basis based on our role in the transaction as an agent as we have concluded that we do not control the use of the print textbooks, and therefore record only the revenue share we earn upon the shipment of a print textbook to a student. For the rental or sale of eTextbooks, we have concluded that we control the service, therefore we recognize revenues and cost of revenues on a gross basis ratably over the term the student has access to the eTextbook. Contract assets are contained within other current assets and other assets on our consolidated balance sheets. Contract assets represent the goods or services that we have transferred to a customer before invoicing the customer. Contract receivables are contained within accounts receivable, net on our consolidated balance sheets and represent unconditional consideration that will be received solely due to the passage of time. Contract liabilities are contained within deferred revenue on our consolidated balance sheets. Deferred revenue primarily consists of advanced payments from students related to rental and subscription performance obligations that have not been satisfied and estimated variable consideration. Deferred revenue related to rental and subscription performance obligations is recognized as revenues ratably over the term for subscriptions or when the services are provided and all other revenue recognition criteria have been met. Deferred revenue related to variable consideration is recognized as revenues during each reporting period based on the estimated amount we believe we will earn over the life of the contract. We have elected a practical expedient to record incremental costs to obtain or fulfill a contract when the amortization period would have been one year or less as incurred. These incremental costs primarily relate to sales commissions costs and are recorded in sales and marketing expense on our consolidated statements of operations. Cost of Revenues Our cost of revenues consists primarily of expenses associated with the delivery and distribution of our products and services. Cost of revenues primarily consists of publisher content fees for eTextbooks, content amortization expense related to content that we develop, license from publishers for which we pay one-time license fees, or acquire through acquisitions, payment processing costs, the payments made to tutors through our Chegg Tutors service, personnel costs and other direct costs related to providing content or services. In addition, cost of revenues includes allocated information technology and facilities costs. Research and Development Costs Our research and development expenses consist of salaries, benefits, and share-based compensation expense for employees on our product, engineering, and technical teams who are responsible for maintaining our website, developing new products, and improving existing products. Research and development costs also include amortization of acquired intangible assets, depreciation expense, technology costs to support our research and development, outside services, and allocated information technology and facilities expenses. We expense substantially all of our research and development expenses as they are incurred. Advertising Costs Advertising costs are expensed as incurred and consist primarily of online advertising and marketing promotional expenditures. During the years ended December 31, 2019 , 2018 , and 2017 , advertising costs were approximately $24.4 million , $17.9 million , and $16.5 million , respectively. Restructuring Charges Restructuring charges are primarily comprised of severance costs, contract and program termination costs, asset impairments, and costs of facility consolidation and closure. Restructuring charges are recorded upon approval of a formal management plan and are included in the results of operations of the period in which such plan is approved and the expense becomes estimable. To estimate restructuring charges, management utilizes assumptions of the number of employees that would be involuntarily terminated and of future costs to operate and eventually vacate duplicate facilities. Severance and other employee separation costs are accrued when it is probable that benefits will be paid and the amount is reasonably estimable. The rates used in determining severance accruals are based on our policies and practices and negotiated settlements. Restructuring charges for employee workforce reductions are recorded upon employee notification for employees whose required continuing service period is 60 days or less and ratably over the employee’s continuing service period for employees whose required continuing service period is greater than 60 days. Share-based Compensation Expense Share-based compensation expense for stock options, restricted stock units (RSUs), performance-based restricted stock units (PSUs), and employee stock purchase plan (ESPP) are accounted for under the fair value method, which requires us to measure the cost of share-based compensation awards based on the grant-date fair value of the award. Share-based compensation expense for our ESPP is estimated at the date of grant using the Black-Scholes-Merton option pricing model while RSUs and PSUs are measured based on the closing fair market value of the Company’s common stock on the date of grant. We recognize share-based compensation expense over the requisite service period, which is generally the vesting period, on a straight-line basis for ESPP and RSUs and on a graded basis for PSUs, contingent on the achievement of performance conditions. These amounts are reduced by estimated forfeitures, which are estimated at the time of the grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Income Taxes We account for income taxes under an asset and liability method whereby deferred tax asset and liability account balances are determined based on differences between the financial reporting and the tax basis of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Valuation allowances are established, when necessary, to reduce deferred tax assets to an amount that is more likely than not to be realized. We record uncertain tax positions on the basis of a two-step process in which (1) we determine whether it is more likely than not that the tax positions will be sustained on the basis of technical merits of the position and (2) for those tax positions that meet the more likely than not recognition threshold, we recognize the tax benefit as the largest amount that is cumulative more than 50% likely to be realized upon ultimate settlement with the related tax authority. Our policy is to include interest and penalties related to unrecognized tax benefits as a component of income tax expense. Net Loss Per Share Basic net loss per share is computed by dividing net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potential shares of common stock, including stock options, RSUs, PSUs, and shares related to convertible senior notes, to the extent dilutive. Basic and diluted net loss per share was the same for each period presented as the inclusion of all potential common shares outstanding would have been anti-dilutive. The following table sets forth the computation of historical basic and diluted net loss per share (in thousands, except per share amounts): Years Ended December 31, 2019 2018 2017 Numerator: Net loss $ (9,605 ) $ (14,888 ) $ (20,283 ) Denominator: Weighted average shares used to compute net loss per share, basic and diluted 119,204 113,251 100,022 Net loss per share, basic and diluted $ (0.08 ) $ (0.13 ) $ (0.20 ) The following potential weighted-average shares of common stock outstanding were excluded from the computation of diluted net loss per share because including them would have been anti-dilutive (in thousands): Years Ended December 31, 2019 2018 2017 Options to purchase common stock 2,395 4,045 3,045 RSUs and PSUs 4,699 7,946 153 Shares related to convertible senior notes 3,526 — — Employee stock purchase plan — — 5 Total common stock equivalents 10,620 11,991 3,203 Shares related to convertible senior notes represent the anti-dilutive impact of our issuance of $345 million in aggregate principal amount of our 2023 notes as the average price of our common stock during the year ended December 31, 2019 was higher than the conversion price of $26.95 . While these shares were anti-dilutive during the year ended December 31, 2019 , they may be dilutive in periods we report net income. However, as a result of the capped call transactions, there will be no economic dilution from the 2023 notes up to $40.68 , as exercise of the capped call instruments will reduce dilution from the 2023 notes that would have otherwise occurred when the average price of our common stock exceeds the conversion price. None of the shares related to our issuance of $800 million in aggregate principal amount of our 2025 notes were anti-dilutive during the year ended December 31, 2019 . The average price of our common stock during the year ended December 31, 2019 was lower than the conversion price of our 2025 notes of $51.56 . See Note 10, “Convertible Senior Notes”, for more information about our convertible senior notes. Foreign Currency Translation The functional currency of our foreign subsidiaries is the local currency. Adjustments resulting from the translation of foreign currencies into U.S. dollars for balance sheet amounts are based on the exchange rates as of the consolidated balance sheet date. Revenues and expenses are translated at average exchange rates during the period. Foreign currency translation gains or losses are included in accumulated other comprehensive loss as a component of stockholders’ equity on the consolidated balance sheets. Gains or losses resulting from foreign currency transactions, which are denominated in currencies other than the entity’s functional currency, are included in other income, net in the consolidated statements of operations and were not material during the years ended December 31, 2019 , 2018 or 2017 . Recent Accounting Pronouncements Recently Issued Accounting Pronouncements Not Yet Adopted In December 2019, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. ASU 2019-12 key changes include hybrid tax regimes, intraperiod tax allocation exception, and interim-period accounting for enacted changes in tax law. Early adoption is permitted, including adoption in any interim period or annual reports for which financial statements have not yet been made available for issuance. The guidance is effective for annual periods beginning after December 15, 2020, and we are currently in the process of evaluating the impact of this guidance. The FASB issued four ASUs related to Accounting Standards Codification (ASC) 326. In November 2019, the FASB issued ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments - Credit Losses. ASU 2019-11 provides codification updates to ASU 2016-13. In May 2019, the FASB issued ASU 2019-05, Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief. ASU 2019-05 provides entities with an option to irrevocably elect the fair value option for eligible instruments. In April 2019, the FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments. ASU 2019-04 provides codification updates to ASU 2016-01 and ASU 2016-13. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . ASU 2016-13 replaces the existing incurred loss impairment model for trade receivables with an expected loss model which requires the use of forward-looking inf |
