Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements and condensed footnotes have been prepared in accordance with the applicable rules and regulations of the Securities and Exchange Commission (the SEC) regarding interim financial reporting. Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles (GAAP) for complete financial statements due to the permitted exclusion of certain disclosures for interim reporting. In the opinion of management, all adjustments (consisting of normal recurring items) considered necessary under GAAP for fair statement of results for the interim periods presented have been included. The results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or for other interim periods or future years. The condensed consolidated balance sheet as of December 31, 2018 is derived from audited financial statements; however, it does not include all of the information and footnotes required by GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2018, which was filed with the SEC on February 27, 2019.
Prior Period Reclassifications	Prior Period Reclassification Certain reclassifications of prior period amounts pertaining to the reclassification of revenues from IT Operations Management (ITOM) products to digital workflow products have been made in Note 18 to conform to the current period presentation. These reclassifications did not result in a restatement of prior period financial statements.
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements have been prepared in conformity with GAAP, and include our accounts and the accounts of our wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated upon consolidation.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements, as well as reported amounts of revenues and expenses during the reporting period. Such management estimates and assumptions include, but are not limited to, evaluating the terms and conditions included within our customer contracts as well as determining stand-alone selling price (SSP) for each distinct performance obligation included in customer contracts with multiple performance obligations, the period of benefit for deferred commissions, purchase price allocation for business combinations, stock-based compensation expenses, the useful life and recoverability of our property and equipment, goodwill and identifiable intangible assets, whether an arrangement is or contains a lease, the discount rate used for operating leases, fair value of convertible notes, income taxes, and legal contingencies. Actual results could differ from those estimates.
Segments	Segments We define the term “chief operating decision maker” to be our Chief Executive Officer. Our chief operating decision maker allocates resources and assesses financial performance based upon discrete financial information at the consolidated level. Accordingly, we have determined that we operate as a single operating and reportable segment.
Concentration of Credit Risk and Significant Customers	Concentration of Credit Risk and Significant Customers Financial instruments potentially exposing us to credit risk consist primarily of cash, cash equivalents, derivative contracts, investments and accounts receivable. We hold cash at financial institutions that management believes are high credit, quality financial institutions and invest in securities with a minimum rating of BBB by Standard & Poor’s, Baa2 by Moody’s, or BBB by Fitch to minimize our credit risks. 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 entering into master netting arrangements, which permit net settlement of transactions with the same counterparty. While the contract or notional amount is often used to express the volume of foreign currency derivative contracts, the amounts potentially subject to credit risk are generally limited to the amounts, if any, by which the counterparties’ obligations under the agreements exceed the obligations of the Company to the counterparties. We are not required to pledge, and are not entitled to receive, cash collateral related to these derivative instruments. We are also exposed to credit risk under the convertible note hedge transactions that may result from counterparties’ non-performance. Credit risk arising from accounts receivable is mitigated due to our large number of customers and their dispersion across various industries and geographies. As of June 30, 2019, we had one customer that represented approximately 10% of our accounts receivable balance. As of December 31, 2018, there were no customers that represented more than 10% of our accounts receivable balance. There were no customers that individually exceeded 10% of our total revenues in any of the periods presented. For purposes of assessing concentration of credit risk and significant customers, a group of customers under common control or customers that are affiliates of each other are regarded as a single customer.
Updated Significant Accounting Policies, Accounting Pronouncements Adopted in 2019, Accounting Pronouncements Adopted in 2018, and New Accounting Pronouncements Pending Adoption	Updated Significant Accounting Policies Leases In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-02, “Leases (Topic 842),” which requires lessees to generally recognize on the balance sheet operating and financing lease liabilities and corresponding right-of-use assets, and to recognize on the income statement the expenses in a manner similar to prior practice. We adopted Topic 842 using the modified retrospective method as of January 1, 2019 and elected the transition option that allows us not to restate the comparative periods in our financial statements in the year of adoption. We also elected the package of transition expedients available for expired or existing contracts, which allowed us to carryforward our historical assessment of (1) whether contracts are or contain leases, (2) lease classification and (3) initial direct costs. We determine if an arrangement is or contains a lease at inception by evaluating various factors, including whether a vendor’s right to substitute an identified asset is substantive. Lease classification is determined at the lease commencement date, on which the leased assets are made available for our use. Operating leases are included in “Operating lease right-of-use assets”, “Current portion of operating lease liabilities”, and “Operating lease liabilities, less current portion” in our condensed consolidated balance sheets. We did not have any material financing leases in any of the periods presented. Right-of-use assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The difference between the total right-of-use assets and total lease liabilities recorded as of January 1, 2019 is primarily due to the derecognition of deferred rent liabilities that were included in “Accrued expenses and other current liabilities” and “Other long-term liabilities”, respectively, in our condensed consolidated balance sheet as of December 31, 2018. Lease payments consist primarily of the fixed payments under the arrangement, less any lease incentives such as rent holidays. We use an estimate of our incremental borrowing rate (IBR) based on the information available at the lease commencement date in determining the present value of lease payments, unless the implicit rate is readily determinable. In determining the appropriate IBR, we consider information including, but not limited to, our credit rating, the lease term, and the currency in which the arrangement is denominated. For leases which commenced prior to our adoption of Topic 842, we used the IBR on January 1, 2019. Our lease terms may include the sole option for us to either renew or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. For our office facility leases, we elected to account for lease and non-lease components as a single lease component. For other arrangements, lease and non-lease components are generally accounted for separately. Additionally, we do not record leases on the balance sheet that, at the lease commencement date, have a lease term of 12 months or less. Derivative financial instruments and hedging activities We use derivative financial instruments to manage foreign currency risks. These derivative contracts consist of forward contracts entered into with various counterparties and are not designated as hedging instruments under applicable accounting guidance. As such, all changes in the fair value of these derivative contracts are recorded in “Interest income and other income (expense), net” on the condensed consolidated statements of comprehensive income (loss), and are intended to offset the foreign currency gains or losses associated with the underlying monetary assets and liabilities. Realized gains (losses) from settlement of the derivative assets and liabilities not designated as hedging instruments are classified as investing activities in the condensed consolidated statement of cash flows. Accounting Pronouncement Adopted in 2019 Leases As described in the “Leases” section above, we adopted Topic 842 using the modified retrospective method as of January 1, 2019 with an immaterial amount of cumulative effect adjustment recorded to our accumulated deficit as of January 1, 2019. As this standard was adopted on a modified prospective basis as of January 1, 2019, the adoption of this standard did not impact our previously reported financial statements for periods ended on or prior to December 31, 2018. Upon adoption, we recorded operating lease right-of-use assets of approximately $334.7 million and corresponding operating lease liabilities of $362.7 million on our condensed consolidated balance sheets. Accounting Pronouncements Adopted in 2018 For details on our adoption of ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” ASU 2016-01, “Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities,” ASU 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory” and other accounting standards adopted in 2018, refer to Note 2, Summary of Significant Accounting Policies, of the notes to our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018, which was filed with the SEC on February 27, 2019. New Accounting Pronouncements Pending Adoption Cloud computing arrangements implementation costs In August 2018, the FASB issued ASU 2018-15, “Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract,” which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The new standard requires capitalized costs to be amortized on a straight-line basis generally over the term of the arrangement, and the financial statement presentation for these capitalized costs would be the same as that of the fees related to the hosting arrangements. This new standard is effective for our interim and annual periods beginning January 1, 2020 and earlier adoption is permitted. This standard could be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. We will adopt this standard on a prospective basis as of January 1, 2020 and are evaluating the impact of our pending adoption of this standard on our condensed consolidated financial statements. Credit losses In June 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which requires a financial asset measured at amortized cost basis to be presented at the net amount expected to be collected, with further clarifications made more recently. For trade receivables, loans, and other financial instruments, we will be required to use a forward-looking expected loss model rather than the incurred loss model for recognizing credit losses which reflects losses that are probable. Credit losses relating to available-for-sale debt securities are required to be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. This new standard is effective for our interim and annual periods beginning January 1, 2020. We are currently evaluating the impact of the adoption of this standard on our condensed consolidated financial statements.
Fair Value Measurements	We determine the fair value of our security holdings based on pricing from our service providers and market prices from industry-standard independent data providers. Such market prices may be quoted prices in active markets for identical assets (Level 1 inputs) or pricing determined using inputs other than quoted prices that are observable either directly or indirectly (Level 2 inputs), such as yield curve, volatility factors, credit spreads, default rates, loss severity, current market and contractual prices for the underlying instruments or debt, broker and dealer quotes, as well as other relevant economic measures. Our equity investments in privately-held companies are not included in the table above and are discussed in Note 3.
Legal Proceedings	From time to time, we are party to litigation and other legal proceedings in the ordinary course of business. While the results of any litigation or other legal proceedings are uncertain, management does not believe the ultimate resolution of any pending legal matters is likely to have a material adverse effect on our financial position, results of operations or cash flows, except for those matters for which we have recorded a loss contingency. We accrue for loss contingencies when it is both probable that we will incur the loss and when we can reasonably estimate the amount of the loss or range of loss. Generally, our subscription agreements require us to defend our customers for third-party intellectual property infringement and other claims. Any adverse determination related to intellectual property claims or other litigation could prevent us from offering our services and adversely affect our financial condition and results of operations.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2019

The accompanying unaudited condensed consolidated financial statements and condensed footnotes have been prepared in accordance with the applicable rules and regulations of the Securities and Exchange Commission (the SEC) regarding interim financial reporting. Accordingly, they do not include all of the information and footnotes required by U.S. generally accepted accounting principles (GAAP) for complete financial statements due to the permitted exclusion of certain disclosures for interim reporting. In the opinion of management, all adjustments (consisting of normal recurring items) considered necessary under GAAP for fair statement of results for the interim periods presented have been included. The results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019 or for other interim periods or future years. The condensed consolidated balance sheet as of December 31, 2018 is derived from audited financial statements; however, it does not include all of the information and footnotes required by GAAP for complete financial statements. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended December 31, 2018, which was filed with the SEC on February 27, 2019.

Prior Period Reclassifications

Prior Period Reclassification

Certain reclassifications of prior period amounts pertaining to the reclassification of revenues from IT Operations Management (ITOM) products to digital workflow products have been made in Note 18 to conform to the current period presentation. These reclassifications did not result in a restatement of prior period financial statements.

Principles of Consolidation

The condensed consolidated financial statements have been prepared in conformity with GAAP, and include our accounts and the accounts of our wholly-owned subsidiaries. All intercompany transactions and balances have been eliminated upon consolidation.

Use of Estimates

The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make certain estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements, as well as reported amounts of revenues and expenses during the reporting period. Such management estimates and assumptions include, but are not limited to, evaluating the terms and conditions included within our customer contracts as well as determining stand-alone selling price (SSP) for each distinct performance obligation included in customer contracts with multiple performance obligations, the period of benefit for deferred commissions, purchase price allocation for business combinations, stock-based compensation expenses, the useful life and recoverability of our property and equipment, goodwill and identifiable intangible assets, whether an arrangement is or contains a lease, the discount rate used for operating leases, fair value of convertible notes, income taxes, and legal contingencies. Actual results could differ from those estimates.

Segments

We define the term “chief operating decision maker” to be our Chief Executive Officer. Our chief operating decision maker allocates resources and assesses financial performance based upon discrete financial information at the consolidated level. Accordingly, we have determined that we operate as a single operating and reportable segment.

Concentration of Credit Risk and Significant Customers

Financial instruments potentially exposing us to credit risk consist primarily of cash, cash equivalents, derivative contracts, investments and accounts receivable. We hold cash at financial institutions that management believes are high credit, quality financial institutions and invest in securities with a minimum rating of BBB by Standard & Poor’s, Baa2 by Moody’s, or BBB by Fitch to minimize our credit risks. 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 entering into master netting arrangements, which permit net settlement of transactions with the same counterparty. While the contract or notional amount is often used to express the volume of foreign currency derivative contracts, the amounts potentially subject to credit risk are generally limited to the amounts, if any, by which the counterparties’ obligations under the agreements exceed the obligations of the Company to the counterparties. We are not required to pledge, and are not entitled to receive, cash collateral related to these derivative instruments. We are also exposed to credit risk under the convertible note hedge transactions that may result from counterparties’ non-performance.

Credit risk arising from accounts receivable is mitigated due to our large number of customers and their dispersion across various industries and geographies. As of June 30, 2019, we had one customer that represented approximately 10% of our accounts receivable balance. As of December 31, 2018, there were no customers that represented more than 10% of our accounts receivable balance. There were no customers that individually exceeded 10% of our total revenues in any of the periods presented. For purposes of assessing concentration of credit risk and significant customers, a group of customers under common control or customers that are affiliates of each other are regarded as a single customer.

Updated Significant Accounting Policies, Accounting Pronouncements Adopted in 2019, Accounting Pronouncements Adopted in 2018, and New Accounting Pronouncements Pending Adoption

Updated Significant Accounting Policies

Leases

In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-02, “Leases (Topic 842),” which requires lessees to generally recognize on the balance sheet operating and financing lease liabilities and corresponding right-of-use assets, and to recognize on the income statement the expenses in a manner similar to prior practice. We adopted Topic 842 using the modified retrospective method as of January 1, 2019 and elected the transition option that allows us not to restate the comparative periods in our financial statements in the year of adoption. We also elected the package of transition expedients available for expired or existing contracts, which allowed us to carryforward our historical assessment of (1) whether contracts are or contain leases, (2) lease classification and (3) initial direct costs.

We determine if an arrangement is or contains a lease at inception by evaluating various factors, including whether a vendor’s right to substitute an identified asset is substantive. Lease classification is determined at the lease commencement date, on which the leased assets are made available for our use. Operating leases are included in “Operating lease right-of-use assets”, “Current portion of operating lease liabilities”, and “Operating lease liabilities, less current portion” in our condensed consolidated balance sheets. We did not have any material financing leases in any of the periods presented.

Right-of-use assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The difference between the total right-of-use assets and total lease liabilities recorded as of January 1, 2019 is primarily due to the derecognition of deferred rent liabilities that were included in “Accrued expenses and other current liabilities” and “Other long-term liabilities”, respectively, in our condensed consolidated balance sheet as of December 31, 2018. Lease payments consist primarily of the fixed payments under the arrangement, less any lease incentives such as rent holidays. We use an estimate of our incremental borrowing rate (IBR) based on the information available at the lease commencement date in determining the present value of lease payments, unless the implicit rate is readily determinable. In determining the appropriate IBR, we consider information including, but not limited to, our credit rating, the lease term, and the currency in which the arrangement is denominated. For leases which commenced prior to our adoption of Topic 842, we used the IBR on January 1, 2019. Our lease terms may include the sole option for us to either renew or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term.

For our office facility leases, we elected to account for lease and non-lease components as a single lease component. For other arrangements, lease and non-lease components are generally accounted for separately. Additionally, we do not record leases on the balance sheet that, at the lease commencement date, have a lease term of 12 months or less.

Derivative financial instruments and hedging activities

We use derivative financial instruments to manage foreign currency risks. These derivative contracts consist of forward contracts entered into with various counterparties and are not designated as hedging instruments under applicable accounting guidance. As such, all changes in the fair value of these derivative contracts are recorded in “Interest income and other income (expense), net” on the condensed consolidated statements of comprehensive income (loss), and are intended to offset the foreign currency gains or losses associated with the underlying monetary assets and liabilities. Realized gains (losses) from settlement of the derivative assets and liabilities not designated as hedging instruments are classified as investing activities in the condensed consolidated statement of cash flows.

Accounting Pronouncement Adopted in 2019

Leases

As described in the “Leases” section above, we adopted Topic 842 using the modified retrospective method as of January 1, 2019 with an immaterial amount of cumulative effect adjustment recorded to our accumulated deficit as of January 1, 2019. As this standard was adopted on a modified prospective basis as of January 1, 2019, the adoption of this standard did not impact our previously reported financial statements for periods ended on or prior to December 31, 2018. Upon adoption, we recorded operating lease right-of-use assets of approximately $334.7 million and corresponding operating lease liabilities of $362.7 million on our condensed consolidated balance sheets.

Accounting Pronouncements Adopted in 2018

For details on our adoption of ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” ASU 2016-01, “Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities,” ASU 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory” and other accounting standards adopted in 2018, refer to Note 2, Summary of Significant Accounting Policies, of the notes to our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018, which was filed with the SEC on February 27, 2019.

New Accounting Pronouncements Pending Adoption

Cloud computing arrangements implementation costs

In August 2018, the FASB issued ASU 2018-15, “Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract,” which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The new standard requires capitalized costs to be amortized on a straight-line basis generally over the term of the arrangement, and the financial statement presentation for these capitalized costs would be the same as that of the fees related to the hosting arrangements. This new standard is effective for our interim and annual periods beginning January 1, 2020 and earlier adoption is permitted. This standard could be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. We will adopt this standard on a prospective basis as of January 1, 2020 and are evaluating the impact of our pending adoption of this standard on our condensed consolidated financial statements.

Credit losses

In June 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which requires a financial asset measured at amortized cost basis to be presented at the net amount expected to be collected, with further clarifications made more recently. For trade receivables, loans, and other financial instruments, we will be required to use a forward-looking expected loss model rather than the incurred loss model for recognizing credit losses which reflects losses that are probable. Credit losses relating to available-for-sale debt securities are required to be recorded through an allowance for credit losses rather than as a reduction in the amortized cost basis of the securities. This new standard is effective for our interim and annual periods beginning January 1, 2020. We are currently evaluating the impact of the adoption of this standard on our condensed consolidated financial statements.

Fair Value Measurements

We determine the fair value of our security holdings based on pricing from our service providers and market prices from industry-standard independent data providers. Such market prices may be quoted prices in active markets for identical assets (Level 1 inputs) or pricing determined using inputs other than quoted prices that are observable either directly or indirectly (Level 2 inputs), such as yield curve, volatility factors, credit spreads, default rates, loss severity, current market and contractual prices for the underlying instruments or debt, broker and dealer quotes, as well as other relevant economic measures.

Our equity investments in privately-held companies are not included in the table above and are discussed in Note 3.

Legal Proceedings

From time to time, we are party to litigation and other legal proceedings in the ordinary course of business. While the results of any litigation or other legal proceedings are uncertain, management does not believe the ultimate resolution of any pending legal matters is likely to have a material adverse effect on our financial position, results of operations or cash flows, except for those matters for which we have recorded a loss contingency. We accrue for loss contingencies when it is both probable that we will incur the loss and when we can reasonably estimate the amount of the loss or range of loss.

Generally, our subscription agreements require us to defend our customers for third-party intellectual property infringement and other claims. Any adverse determination related to intellectual property claims or other litigation could prevent us from offering our services and adversely affect our financial condition and results of operations.