| Description of business, basis of presentation, principles of consolidation, and summary of significant accounting policies | Description of Business and Summary of Significant Accounting Policies Description of Business Palo Alto Networks, Inc. (the “Company,” “we,” “us,” or “our”), located in Santa Clara, California, was incorporated in March 2005 under the laws of the State of Delaware and commenced operations in April 2005. We offer a platform that empowers enterprises, service providers, and government entities to secure their organizations by safely enabling applications and data running in their networks, on their endpoints, and in the cloud, and by preventing breaches that stem from targeted cyberattacks. Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) . The consolidated financial statements include all adjustments necessary for a fair presentation of our annual results. All adjustments are of a normal recurring nature. Certain prior period amounts have been reclassified to conform to our current period presentation. In addition, certain prior period amounts have been adjusted due to our retrospective adoption of new accounting guidance related to revenue from contracts with customers and new accounting guidance related to the presentation of restricted cash and cash equivalents in the statement of cash flows. Refer to “Recently Adopted Accounting Pronouncements” below for more information. Principles of Consolidation The consolidated financial statements include our accounts and our wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Such management estimates include, but are not limited to the standalone selling price for our products and services, share-based compensation, fair value of assets acquired and liabilities assumed in business combinations, the assessment of recoverability of our property and equipment, identified intangibles and goodwill, future taxable income, manufacturing partner and supplier liabilities, fair value of debt component of convertible notes, cease-use loss related to facility exit, deferred contract cost benefit period, and loss contingencies. We base our estimates on historical experience and also on assumptions that we believe are reasonable. Actual results could differ materially from those estimates. Concentrations Financial instruments that subject us to concentrations of credit risk consist primarily of cash and cash equivalents, investments, accounts receivable, and derivative contracts. We invest only in high-quality credit instruments and maintain our cash and cash equivalents and available-for-sale investments in fixed income securities. Management believes that the financial institutions that hold our investments are financially sound and, accordingly, are subject to minimal credit risk. Deposits held with banks may exceed the amount of insurance provided on such deposits. Our derivative contracts expose us to credit risk to the extent that the counterparties may be unable to meet the terms of the arrangement. We mitigate this credit risk by transacting with major financial institutions with high credit ratings and also enter into master netting arrangements, which permit net settlement of transactions with the same counterparty. We are not required to pledge, and are not entitled to receive, cash collateral related to these derivative instruments. We do not enter into derivative contracts for trading or speculative purposes. Our accounts receivables are primarily derived from our distributors representing various geographical locations. We perform ongoing credit evaluations and generally do not require collateral on accounts receivable. We maintain an allowance for doubtful accounts for estimated potential credit losses. As of July 31, 2019 , three distributors represented 29.9% , 18.9% , and 14.2% of our gross accounts receivable. For fiscal 2019 , four distributors represented 31.8% , 22.1% , 10.7% , and 10.0% of our total revenue. We rely on an electronics manufacturing services provider (“EMS provider”) to assemble most of our products and sole source component suppliers for a certain number of our components. Comprehensive Loss Comprehensive loss is comprised of net loss and other comprehensive income (loss). Our other comprehensive income (loss) includes unrealized gains and losses on available-for-sale investments and unrealized gains and losses on cash flow hedges. Foreign Currency Transactions The functional currency of our foreign subsidiaries is the U.S. dollar. Monetary assets and liabilities denominated in foreign currencies have been remeasured into U.S. dollars using the exchange rates in effect at the balance sheet dates. Foreign currency denominated income and expenses have been remeasured using the average exchange rates in effect during each period. Foreign currency remeasurement gains and losses and foreign currency transaction gains and losses are not significant to the financial statements. Fair Value We define fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities which are required to be recorded at fair value, we consider the principal or most advantageous market in which to transact and the market-based risk. We apply fair value accounting for all financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. Goodwill, intangible assets, and other long-lived assets are measured at fair value on a nonrecurring basis, only if impairment is indicated. The carrying amounts reported in the consolidated financial statements approximate the fair value for cash and cash equivalents, accounts receivable, accounts payable, and accrued liabilities, due to their short-term nature. Cash, Cash Equivalents, and Investments We consider all highly liquid investments with original maturities of three months or less at date of purchase to be cash equivalents. Investments not considered cash equivalents and with maturities one year or less from the consolidated balance sheet date are classified as short-term investments. Investments with maturities greater than one year from the consolidated balance sheet date are classified as long-term investments. We classify our investments in marketable debt securities as available-for-sale at the time of purchase since it is our intent that these investments are available for current operations, and include these investments on our consolidated balance sheets as cash equivalents, short-term investments, or long-term investments depending on their maturity. These investments are considered impaired when a decline in fair value is judged to be other-than-temporary. We consult with our investment managers and consider available quantitative and qualitative evidence in evaluating potential impairment of our investments on a quarterly basis. If the cost of an individual investment exceeds its fair value, we evaluate, among other factors, general market conditions, the duration and extent to which the fair value is less than cost, and our intent and ability to hold the investment. Once a decline in fair value is determined to be other-than-temporary, an impairment charge is recorded and a new cost basis in the investment is established. Accounts Receivable Trade accounts receivable are recorded at the invoiced amount, net of allowances for doubtful accounts. The allowance for doubtful accounts is based on our assessment of the collectability of accounts. Management regularly reviews the adequacy of the allowance for doubtful accounts by considering the age of each outstanding invoice, each channel partner’s expected ability to pay, and the collection history with each channel partner, when applicable, to determine whether a specific allowance is appropriate. Accounts receivable deemed uncollectible are charged against the allowance for doubtful accounts when identified. As of July 31, 2019 and 2018 , the allowance for doubtful accounts activity was not significant. Derivatives Our derivative financial instruments are recorded at fair value, on a gross basis, as either assets or liabilities in our consolidated balance sheets. Gains or losses related to our cash flow hedges are recorded as a component of accumulated other comprehensive income (loss) (“AOCI”) in our consolidated balance sheets and are reclassified into the financial statement line item associated with the underlying hedged transaction in our consolidated statements of operations when the underlying hedged transaction is recognized in earnings. If it becomes probable that the hedged transaction will not occur, the cumulative unrealized gain or loss is reclassified immediately from AOCI into the financial statement line item associated with the underlying hedged transaction in our consolidated statements of operations. Gains or losses related to non-designated derivative instruments are recognized in other income (expense), net in our consolidated statements of operations for each period until the instrument matures, is terminated, is re-designated as a qualified cash flow hedge, or is sold. Derivatives designated as cash flow hedges are classified in our consolidated statements of cash flows in the same manner as the underlying hedged transaction, primarily within cash flows from operating activities. Property and Equipment Property and equipment are stated at cost, less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, generally three to ten years. Leasehold improvements are depreciated over the shorter of the estimated useful lives of the improvements or the remaining lease term. Business Combinations We include the results of operations of the businesses that we acquire as of the respective dates of acquisition. We allocate the fair value of the purchase price of our acquisitions to the tangible assets acquired, liabilities assumed, and intangible assets acquired, based on their estimated fair values. The excess of the purchase price over the fair values of these identifiable assets and liabilities is recorded as goodwill. Additional information existing as of the acquisition date but unknown to us may become known during the remainder of the measurement period, not to exceed 12 months from the acquisition date, which may result in changes to the amounts and allocations recorded. Intangible Assets Purchased intangible assets with finite lives are carried at cost, less accumulated amortization. Amortization is computed over the estimated useful lives of the respective assets. Acquisition-related in-process research and development represents the fair value of incomplete research and development projects that have not reached technological feasibility as of the date of acquisition. Initially, these assets are not subject to amortization. Assets related to projects that have been completed are transferred to developed technology, which are subject to amortization. Impairment of Goodwill, Intangible Assets, and Other Long-Lived Assets Goodwill is evaluated for impairment on an annual basis in the fourth quarter of our fiscal year, and whenever events or changes in circumstances indicate the carrying amount of goodwill may not be recoverable. We have elected to first assess qualitative factors to determine whether it is more likely than not that the fair value of our single reporting unit is less than its carrying amount, including goodwill. If we determine that it is more likely than not that the fair value of our single reporting unit is less than its carrying amount, then the quantitative impairment test will be performed. Under the quantitative impairment test, if the carrying amount of our single reporting unit exceeds its fair value, we will recognize an impairment loss in an amount equal to that excess, but limited to the total amount of goodwill. We evaluate events and changes in circumstances that could indicate carrying amounts of purchased intangible assets and other long-lived assets may not be recoverable. When such events or changes in circumstances occur, we assess the recoverability of these assets by determining whether or not the carrying amount will be recovered through undiscounted expected future cash flows. If the total of the future undiscounted cash flows is less than the carrying amount of an asset, we record an impairment loss for the amount by which the carrying amount of the asset exceeds the fair value of the asset. Through July 31, 2019 , we have not recognized any impairment losses on our goodwill and intangible assets. During the year ended July 31, 2017, we recognized an impairment loss of $20.9 million on property and equipment related to the relocation of our corporate headquarters. We did not recognize any impairment losses on our other long-lived assets during the years ended July 31, 2019 and 2018, or prior to fiscal 2017. Manufacturing Partner and Supplier Liabilities We outsource most of our manufacturing, repair, and supply chain management operations to our EMS provider and payments to it are a significant portion of our cost of product revenue. Although we could be contractually obligated to purchase manufactured products and components, we generally do not own the manufactured products and components. Product title transfers from our EMS provider to us and immediately to our channel partners upon shipment. Our EMS provider assembles our products using design specifications, quality assurance programs, and standards that we establish and it procures components and assembles our products based on our demand forecasts. These forecasts represent our estimates of future demand for our products based upon historical trends and analysis from our sales and product management functions as adjusted for overall market conditions. If the actual component usage and product demand are significantly lower than forecast, we record a liability for manufacturing purchase commitments in excess of our forecasted demand including costs for excess components or for carrying costs incurred by our manufacturing partners and component suppliers. Through July 31, 2019 , we have not accrued any significant costs associated with this exposure. Convertible Senior Notes In accounting for the issuance of our convertible senior notes, we separate the notes into liability and equity components. The carrying amount of the liability component is calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option is determined by deducting the fair value of the liability component from the par value of the notes as a whole. This difference represents a debt discount that is amortized to interest expense using the effective interest method over the term of the notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. In accounting for the transaction costs related to the issuance of the notes, we allocate the total amount incurred to the liability and equity components using the same proportions as the proceeds from the notes. Transaction costs attributable to the liability component are netted with the liability component and amortized to interest expense using the effective interest method over the term of the notes. Transaction costs attributable to the equity component are netted with the equity component of the notes in additional paid-in capital in the consolidated balance sheets. When the notes are convertible, the net carrying amount of the notes is classified as a current liability and a portion of the equity component representing the conversion option is reclassified to temporary equity in our consolidated balance sheets. The portion of the equity component classified as temporary equity is measured as the difference between the principal and net carrying amount of the notes, excluding debt issuance costs. Revenue Recognition Our revenue consists of product revenue and subscription and support revenue. Revenue is recognized when control of promised products, subscriptions and support services are transferred to customers with the expected consideration in exchange for those products and services. Depending on who the contract is with, our customers are either our channel partners or our end-customers. 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. Revenues are reported net of sales taxes. Shipping charges billed to channel partners are included in revenues and related costs are included in cost of revenue. Product Revenue Product revenue is derived primarily from sales of our appliances. Product revenue also includes revenue derived from software licenses of Panorama and the VM-Series. Our appliances and software licenses include a broad set of built-in networking and security features and functionalities. We recognize product revenue at the time of hardware shipment or delivery of software license. Subscription and Support Revenue Subscription and support revenue is derived primarily from sales of our subscription and support offerings. We recognize subscription and support revenue over time as the services are performed. Our contractual subscription and support contracts are typically one to five years . Contracts with Multiple Performance Obligations The majority of our contracts with our customers include various combinations of our products and subscriptions and support. Our appliances and software licenses have significant standalone functionalities and capabilities. Accordingly, these appliances and software licenses are distinct from our subscriptions and support services as the customer can benefit from the product without these services and such services are separately identifiable within the contract. We account for multiple agreements with a single customer as a single contract if the contractual terms and/or substance of those agreements indicate that they may be so closely related that they are, in effect, parts of a single contract. The amount of consideration we expect to receive in exchange for delivering on the contract is allocated to each performance obligation based on its relative standalone selling price. If a contract contains a single performance obligation, no allocation is required. We establish standalone selling price using the prices charged for a deliverable when sold separately. If the standalone selling price is not observable through past transactions, we estimate the standalone selling price based on our pricing model and our go-to-market strategy, which include factors such as type of sales channel (reseller, distributor, or end-customer), the geographies in which our offerings were sold (domestic or international), and offering type (products, subscriptions, or support). Deferred Revenue We record deferred revenue when cash payments are received or due in advance of our performance. Our payment terms typically require payment within 30 to 45 days of the date we issue an invoice. The current portion of deferred revenue represents the amounts that are expected to be recognized as revenue within one year of the consolidated balance sheet date. Deferred Contract Costs We defer contract costs that are recoverable and incremental to obtaining customer sales contracts. Contract costs, which primarily consist of sales commissions, are amortized on a systematic basis that is consistent with the transfer to the customer of the goods or services to which the asset relates. Sales commissions paid for initial contracts are generally not commensurate with the commissions paid for renewal contracts, given the substantive difference in commission rates in proportion to their respective contract values. Sales commissions for initial contracts that are not commensurate are amortized over a benefit period of five years , consistent with the revenue recognition pattern of the performance obligations in the related contracts including expected renewals. The benefit period is determined by taking into consideration contract length, technology life, and other quantitative and qualitative factors. The expected renewals are estimated based on historical renewal trends. Sales commissions for initial contracts that are commensurate and sales commissions for renewal contracts are amortized over the related contractual period in proportion to the revenue recognized. We classify deferred contract costs as short-term or long-term based on when we expect to recognize the expense. Short-term deferred contract costs are included in prepaid expenses and other current assets and long-term deferred contract costs are included in other assets in our consolidated balance sheets. Deferred contract costs are periodically reviewed for impairment. The amortization of deferred contract costs is included in sales and marketing expense in our consolidated statements of operations. Software Development Costs Internally developed software includes security software developed to meet our internal needs to provide cloud-based subscription offerings to our end-customers and business software that we customize to meet our specific operational needs. These capitalized costs consist of internal compensation related costs and external direct costs incurred during the application development stage and will be amortized over a useful life of three to five years. As of July 31, 2019 and 2018, we capitalized as other assets on our consolidated balance sheets $44.9 million and $23.0 million in costs, respectively, net of accumulated amortization, for security software developed to meet our internal needs to provide our cloud-based subscription offerings. We recognized amortization expense of $12.9 million , $4.3 million , and $1.2 million related to these capitalized costs as cost of subscription and support revenue in our consolidated statements of operations during the years ended July 31, 2019, 2018, and 2017, respectively. The costs to develop software that is marketed externally have not been capitalized as we believe our current software development process is essentially completed concurrent with the establishment of technological feasibility. As such, all related software development costs are expensed as incurred and included in research and development expense in our consolidated statements of operations. Share-Based Compensation Compensation expense related to share-based transactions, including employee and non-employee director awards, is measured and recognized in the financial statements based on fair value on the grant date. We recognize share-based compensation expense for awards with only service conditions on a straight-line basis over the requisite service period of the related award. We recognize share-based compensation expense for awards with market conditions and awards with performance conditions on a straight-line basis over the requisite service period for each separately vesting portion of the award and, for awards with performance conditions, when it is probable that the performance condition will be achieved. We account for forfeitures of all share-based payment awards when they occur. Leases We rent our facilities under operating lease agreements and recognize related rent expense on a straight-line basis over the term of the lease. Some of our lease agreements contain rent holidays, scheduled rent increases, lease incentives, and renewal options. Rent holidays and scheduled rent increases are included in the determination of rent expense to be recorded over the lease term. Lease incentives are recognized as a reduction of rent expense on a straight-line basis over the term of the lease. Renewals are not assumed in the determination of the lease term unless they are deemed to be reasonably assured at the inception of the lease. We begin recognizing rent expense on the date that we obtain the legal right to use and control the leased space. Upon exiting a leased property before the lease term expires, we assess the fair value of our remaining obligation under the lease and record a cease-use loss, if needed. The cease-use loss is calculated as the present value of the amount by which the remaining lease obligation, adjusted for the effects of any deferred items recognized under the lease and related costs, exceeds the estimated sublease rentals that could be reasonably obtained. The cease-use loss will be adjusted as a result of the remeasurement of the cease-use liability if the timing or amount of estimated cash flows change. Income Taxes We account for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in our financial statements or tax returns. In addition, deferred tax assets are recorded for the future benefit of utilizing net operating losses and research and development credit carryforwards. Valuation allowances are provided when necessary to reduce deferred tax assets to the amount expected to be realized. Significant judgment is required in determining any valuation allowance recorded against deferred tax assets. In assessing the need for a valuation allowance, we consider all available evidence, including past operating results, estimates of future taxable income, and the feasibility of tax planning strategies. In the event that we change our determination as to the amount of deferred tax assets that can be realized, we will adjust our valuation allowance with a corresponding impact to the provision for income taxes in the period in which such determination is made. We apply the authoritative accounting guidance prescribing a threshold and measurement attribute for the financial recognition and measurement of a tax position taken or expected to be taken in a tax return. We recognize liabilities for uncertain tax positions based on a two-step process. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step requires us to estimate and measure the tax benefit as the largest amount that is more likely than not to be realized upon ultimate settlement. Loss Contingencies We are subject to the possibility of various loss contingencies arising in the ordinary course of business. In determining loss contingencies, we consider the likelihood of loss or impairment of an asset, or the incurrence of a liability, as well as our ability to reasonably estimate the amount of loss. An estimated loss contingency is accrued when it is probable that an asset has been impaired or a liability has been incurred and the amount of loss can be reasonably estimated. If we determine that a loss is possible and the range of the loss can be reasonably determined, then we disclose the range of the possible loss. We regularly evaluate current information available to us to determine whether an accrual is required, an accrual should be adjusted or a range of possible loss should be disclosed. Recently Adopted Accounting Pronouncements Implementation Costs Incurred in a Cloud Computing Arrangement In August 2018, the Financial Accounting Standards Board (“FASB”) issued authoritative guidance on customers’ accounting for implementation costs incurred in a cloud computing arrangement that is a service contract, which requires customers to apply internal-use software guidance to determine the implementation costs that are able to be capitalized. Under the new standard, capitalized implementation costs are generally amortized over the term of the arrangement, beginning when the module or component of the hosting arrangement is ready for its intended use. We early adopted this standard in our second quarter of fiscal 2019 on a prospective basis. The adoption of the standard did not have a material impact on our consolidated financial statements. Business Combinations - Definition of a Business In January 2017, the FASB issued authoritative guidance clarifying the definition of a business to assist companies with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. We adopted this standard in our first quarter of fiscal 2019 on a prospective basis. The adoption of the standard did not have an impact on our consolidated financial statements. Statement of Cash Flows - Restricted Cash In November 2016, the FASB issued authoritative guidance on the presentation of restricted cash or restricted cash equivalents in the statement of cash flows. Under the new standard, restricted cash or restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. We adopted this standard in our first quarter of fiscal 2019 on a retrospective basis. The adoption of the standard did not have a material impact on our consolidated financial statements because our restricted cash balance has not been material. Income Taxes - Intra-Entity Asset Transfers In October 2016, the FASB issued authoritative guidance requiring the recognition of income tax consequences of an intra-entity transfer of an asset, other than inventory, when the transfer occurs. We adopted the standard in our first quarter of fiscal 2019 on a modified retrospective basis. As a result, we recorded the cumulative effect of the change as an increase to accumulated deficit of $28.3 million , with a corresponding decrease to prepaid expenses and other current assets and other assets in our consolidated balance sheets as of August 1, 2018, the date of adoption. The cumulative effect adjustment represents the reclassification of unrecognized income tax effects from intra-entity transfers of assets other than inventory that occurred prior to the date of adoption. Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued new authoritative guidance addressing eight specific cash flow issues with the objective of reducing the existing diversity in practice in how certain transactions are presented and classified in the statement of cash flows. We adopted this standard in our first quarter of fiscal 2019 on a retrospective basis. The adoption of the standard did not have an impact on our consolidated financial statements. Financial Instruments - Recognition and Measurement In January 2016, the FASB issued authoritative guidance requiring equity instruments to be measured at fair value with changes in fair value recognized through net income. We adopted this standard in our first quarter of fiscal 2019 on a prospective basis for non-marketable equity securities and a modified retrospective basis for marketable equity investments. The adoption of the standard did not have an impact on our consolidated financial statements. Revenue Recognition In May 2014, the FASB issued new authoritative guidance on revenue from contracts with customers. The new standard provides principles for recognizing revenue when control of promised goods or services is transferred to customers with the expected consideration in exchange for those goods or services, as well as guidance on the recognition of costs related to obtaining and fulfilling customer contracts. The standard also requires expanded disclosures about the nature, amount, timing, and uncertainty of revenues and cash flows arising from customer contracts, including significant judgments and chan |
