Description of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Description of Business	Description of Business and Summary of Significant Accounting Policies New Relic, Inc. (the “Company” or “New Relic”) was incorporated in Delaware on February 20, 2008, when it converted from a Delaware limited liability company called New Relic Software, LLC, which was formed in Delaware in September 2007. The Company is a provider of an integrated, multi-tenant, cloud-based instrumentation and analytics platform that enables users to collect, store and analyze massive amounts of data in real time.
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation—The consolidated financial statements include the accounts of New Relic and its subsidiaries. These consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP. All intercompany balances and transactions have been eliminated in consolidation. Effective April 1, 2018, the Company adopted the requirements of Accounting Standard Update 2014-09, Revenue from Contracts with Customers: Topic 606 (“ASC 606”), using the modified retrospective method. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods presented, ASC 605, Revenue Recognition (“ASC 605”).
Foreign Currency Translation and Transactions	Foreign Currency Translation and Transactions—The functional currency of the Company’s foreign subsidiaries is the U.S. dollar. The Company translates all monetary assets and liabilities denominated in foreign currencies into U.S. dollars using the exchange rates in effect at the balance sheet dates and other assets and liabilities using historical exchange rates. Foreign currency denominated revenue and expenses have been re-measured using the average exchange rates in effect during each period. Foreign currency re-measurement gains and losses have been included in other income (expense).
Use of Estimates	Use of Estimates—The preparation of the Company’s 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 income and expenses during the reporting period. Significant items subject to such estimates and assumptions include the fair value of share-based awards, fair value of purchased intangible assets and goodwill, fair value of debt and equity components related to the 0.5% convertible senior notes due 2023 (the “Notes”), useful lives of purchased intangible assets, unrecognized tax benefits, expected benefit period for deferred commissions and the capitalization and estimated useful life of the Company’s software development costs. These estimates are based on information available as of the date of the consolidated financial statements; therefore, actual results could differ from management’s estimates.
Segments	Segments—The Company’s chief operating decision maker is the Chief Executive Officer, who reviews financial information presented on a consolidated basis, accompanied by information about revenue by geographic region. Accordingly, the Company has determined that it has a single reportable segment.
Cash and Cash Equivalents	Cash and Cash Equivalents—The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash and cash equivalents.
Restricted Cash	Restricted Cash—The Company has an agreement to maintain cash balances at a financial institution as collateral for letters of credit relating to the Company’s property leases.
Short-term Investments	Short-term Investments—Short-term investments consist of money market funds, certificates of deposit, commercial paper, U.S. treasury securities, U.S. agency securities, and corporate debt securities, and are classified as available-for-sale securities. The Company has classified its investments as current based on the nature of the investments and their availability for use in current operations. Available-for-sale securities are carried at fair value with unrealized gains and losses reported as a component of accumulated other comprehensive income, while realized gains and losses are reported within the statement of operations. The Company reviews its debt securities classified as short-term investments on a regular basis to evaluate whether or not any security has experienced an other-than-temporary decline in fair value. The Company considers factors such as the length of time and extent to which the market value has been less than the cost, the financial position and near-term prospects of the issuer, and the Company’s intent to sell, or whether it is more likely than not the Company will be required to sell the investment before recovery of the investment’s amortized-cost basis. If the Company determines that an other-than-temporary decline exists in one of these securities, the respective investment would be written down to fair value. For debt securities, the portion of the write-down related to credit loss would be recognized to other income, net in the consolidated statement of operations. Any portion not related to credit loss would be included in accumulated other comprehensive income (loss).
Business Combinations	Business Combinations—The Company recognizes identifiable assets acquired and liabilities assumed at their acquisition date fair value. Goodwill as of the acquisition date is measured as the excess of consideration transferred over the net of the acquisition date fair values of the assets acquired and the liabilities assumed. While the Company uses its best estimates and assumptions as a part of the purchase price allocation process to accurately value assets acquired and liabilities assumed at the acquisition date, its estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company records adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill to the extent that the Company identifies adjustments to the preliminary purchase price allocation. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to the Company’s consolidated statements of operations.
Property and Equipment	Property and Equipment—Property and equipment are stated at cost. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets. The Company uses an estimated useful life of three years for employee-related computers and software, three years for other office equipment and site-related computer hardware, and five years for furniture. Leasehold improvements are amortized over the shorter of the lease-term or the estimated useful life of the related asset. Down payments for property and equipment are recorded at cost and included in other assets in the accompanying consolidated balance sheet. Once the corresponding property and equipment item has been received, it will be reclassified to property and equipment and depreciated.
Revenue Recognition	Revenue Recognition—The Company generates revenue from subscription-based arrangements that allow customers to access its products. The Company determines 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; and •recognition of revenue, when, or as, the Company satisfies a performance obligation. Revenue from subscription-based arrangements is recognized on a ratable basis over the contractual subscription period of the arrangement beginning when or as control of the promised goods or services is transferred to the customer. Deferred revenue consists of billings or payments received in advance of revenue being recognized. Deferred Revenue—Deferred revenue consists of billings or payments received in advance of revenue being recognized. The Company generally invoices its customers monthly, quarterly, or annually. Deferred revenue that will be recognized during the succeeding 12-month period is recorded as current deferred revenue and the remaining portion is recorded as non-current deferred revenue. Revenue Recognition The Company offers a comprehensive suite of products delivered on its open and extensible cloud-based platform that enable organizations to collect, store and analyze massive amounts of data in real time so they can better operate their applications and infrastructure and improve their digital customer experience. The Company generates revenue by selling subscription-based arrangements that allow its customers to access its cloud-based platform. The Company determines revenue recognition through the following steps: (i) identification of the contract, or contracts with a customer, (ii) identification of the performance obligations in the contract, (iii) determination of the transaction price, (iv) allocation of the transaction price to the performance obligations in the contract, and (v) recognition of revenue, when, or as, the Company satisfies a performance obligation. Subscription revenue is recognized on a ratable basis over the contractual subscription period of the arrangement beginning when or as control of the promised goods or services is transferred to the customer. Deferred revenue consists of billings or payments received in advance of revenue being recognized. ASC 606 Adoption Impact The Company recognized the cumulative effect of applying ASC 606 as an adjustment to the opening balance of accumulated deficit at April 1, 2018. The comparative information has not been restated and continues to be reported under the accounting standards in effect for the periods prior to adoption, ASC 605. In connection with the adoption of ASC 606, the Company also adopted ASC 340-40, Other Assets and Deferred Costs - Contracts with Customers, which requires the deferral of incremental costs of obtaining a contract with a customer. Collectively, the Company refers to ASC 606 and ASC 340-40 as the “new standard.” The primary impact of adopting the new standard relates to the deferral of incremental commission costs of obtaining contracts. Previously, the Company recorded commissions as sales and marketing expenses as incurred. Under the new standard, the Company capitalizes incremental commissions related to initial contracts and amortizes such costs over the expected period of benefit, which the Company has determined to be three years. With regards to incremental commissions related to renewal contracts, the Company has adopted the practical expedient to expense such commissions as incurred, as the commission paid on renewals are commensurate and the contract periods are generally one year or less. The Company has adopted ASC 606 in the first quarter of fiscal year 2019 using the modified retrospective approach and applied the standard to all contracts as of April 1, 2018. The cumulative effect of applying the new standard was recognized on April 1, 2018. See below for the impact of adopting the new standard. Adoption of the new standard resulted in changes to the Company’s accounting policies for revenue recognition, commissions and deferred commissions as discussed below. The Company recorded a net reduction to the opening balance of accumulated deficit of $40.8 million as of April 1, 2018 due to the cumulative impact of adopting the new standard. The primary impact of adopting the new standard relates to the deferral of $40.6 million in incremental commission costs of obtaining subscription contracts. Under ASC 605, the Company recorded commissions as sales and marketing expenses as incurred. Under the new standard, the Company capitalizes incremental commissions related to initial contracts and amortizes these costs over a period of benefit determined to be three years. The remaining impact of adopting the new standard is immaterial. Practical Expedients and Exemptions The Company applied ASC 606 using the following practical expedients: (i) costs of obtaining contracts with customers are expensed when the amortization period would have been one year or less; and (ii) contract acquisition costs are calculated based on a portfolio of contracts with similar characteristics instead of on a contract-by-contract analysis. The Company receives payments from customers based upon billing cycles. As the Company performs under customer contracts, its right to consideration that is unconditional is considered to be accounts receivable. If the Company’s right to consideration for such performance is contingent upon a future event or satisfaction of additional performance obligations, the amount of revenues the Company has recognized in excess of the amount it has billed to the customer is considered to be a contract asset. Contract assets are immaterial, and as a result, the Company has no asset impairment charges related to contract assets in the period. Deferred revenue represents considerations received from customers in excess of revenues recognized. Revenue recognized during the year ended March 31, 2019, which was included in the deferred revenue balances at the beginning of the period, was $189.4 million. The satisfaction of performance obligations typically lags behind payments received in substantially all of our subscription arrangements, which may lead to an increase in the Company’s deferred revenue balance over time. Movements between contract assets and receivables was not significant during the year ended March 31, 2019. Deferred Commission Costs (Contract Acquisition Costs) In connection with the adoption of ASC 606, the Company is required to capitalize certain contract acquisition costs primarily consisting of commissions. As of April 1, 2018, the date of adoption of ASC 340-40, the Company had $40.6 million capitalized in deferred contract acquisition costs related to contracts where the benefit period had not yet expired. During the year ended March 31, 2019, amortization from amounts capitalized was $25.9 million, and amounts expensed as incurred were $9.0 million. The Company had no impairment loss in relation to costs capitalized. Remaining Performance Obligations The Company’s contracts with customers generally include one main performance obligation, which is access to our SaaS-based products and platform. Within our main performance obligation, each service is generally considered a distinct stand-ready obligation that is recognized over the contract term based on the passage of time. As of March 31, 2019, the unrecognized transaction price related to remaining performance obligations was $498.3 million. The Company expects to recognize more than 93% of the remaining performance obligations over the next 24 months, with the remainder recognized thereafter. Modification From time to time the Company modifies contracts with its customers. These modifications generally result in an extension of the contract term and/or increase in the subscription product. These modifications are generally accounted for as a termination of the old contract and a creation of a new contract because the additional performance obligations are considered distinct and priced at stand-alone selling price. During the year ended March 31, 2019, the impact of modification has not been significant.
Cost of Revenue	Cost of Revenue—Cost of revenue consists of expenses relating to data center operations, hosting-related costs, payment processing fees, depreciation and amortization, consulting costs, and salaries and benefits of operations and global customer support personnel.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts—Accounts receivable are recorded at the invoiced amount, net of allowances for doubtful accounts. The allowance for doubtful accounts is based on the Company’s assessment of the collectability of accounts. The Company regularly reviews the adequacy of the allowance for doubtful accounts by considering the age of each outstanding invoice and the collection history of each customer to determine whether a specific allowance is appropriate. Accounts receivable deemed uncollectable are charged against the allowance for doubtful accounts when identified.
Software Development Costs	Software Development Costs—The Company capitalizes certain development costs incurred in connection with its internal use software and website. These capitalized costs are primarily related to its software tools that are hosted by the Company and accessed by its customers on a subscription basis. Costs incurred in the preliminary stages of development are expensed as incurred. Once an application has reached the development stage, internal and external costs, if direct and incremental, are capitalized until the software is substantially complete and ready for its intended use. Capitalization ceases when the software is released or made available. The Company also capitalizes costs related to specific upgrades and enhancements when it is probable the expenditures will result in additional features and functionality. Maintenance costs are expensed as incurred. Internal use software is amortized on a straight-line basis over its estimated useful life, generally three years.
Commissions	Commissions—Sales commissions
Advertising Expenses	Advertising Expenses—Advertising is expensed as incurred and is included in sales and marketing in the consolidated statements of operations.
Operating Leases	Operating Leases—The Company leases office space and data center facilities under operating leases. Certain lease agreements contain rent holidays, allowances, and rent escalation provisions. The Company recognizes rent expense under such leases on a straight-line basis over the term of the lease. Lease renewal periods are considered on a lease-by-lease basis in determining the lease term.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets—Long-lived assets, such as property and equipment, acquired intangible assets, and capitalized software development costs subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. If circumstances require a long-lived asset be tested for possible impairment, the Company first compares undiscounted cash flows expected to be generated by the asset to its carrying value. If the carrying value of the long-lived asset is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. Fair value is determined through various valuation techniques, including discounted cash flow models, quoted market values, and third-party independent appraisals, as considered necessary.
Goodwill	Goodwill—Goodwill represents the excess of the purchase price of an acquired business over the fair value of the underlying net tangible and intangible assets. Goodwill is evaluated for impairment annually in the third quarter of the Company’s fiscal year, and whenever events or changes in circumstances indicate the carrying value of goodwill may not be recoverable. Triggering events that may indicate impairment include, but are not limited to, a significant adverse change in customer demand or business climate that could affect the value of goodwill or a significant decrease in expected cash flows.
Intangible Assets	Intangible Assets—Intangible assets consist of identifiable intangible assets, primarily developed technology, resulting from the Company’s acquisitions. Acquired intangible assets are recorded at cost, net of accumulated amortization. Intangible assets are amortized on a straight-line basis over their estimated useful lives.
Stock-Based Compensation	Stock-Based Compensation—The Company estimates the fair value of share-based awards on the date of grant. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the statements of operations. The Company recognizes compensation expense over the vesting period of the entire award using the straight-line attribution method. These amounts are reduced by an estimated forfeiture rate. The forfeiture rate is estimated based on actual cancellation experience and is applied to all share-based awards. The rate is estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The Company selected the Black-Scholes option-pricing model as the method for determining the estimated fair value for stock options and shares pursuant to the Company’s 2014 Employee Stock Purchase Plan, or ESPP. The Black-Scholes option-pricing model requires the use of highly subjective and complex assumptions, which determine the fair value of share-based awards, including the option’s expected term and the price volatility of the underlying stock. The authoritative guidance prohibits the recognition of a deferred tax asset for an excess tax benefit that has not yet been included in the Company’s tax return. As a result, the Company will only recognize an excess tax benefit from stock-based compensation in additional paid-in capital in the period in which it is included in the Company’s tax return.
Fair Value Measurements	Fair Value Measurements—The Company defines 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 that are required to be recorded at fair value, the Company considers the principal or most advantageous market in which to transact and the market-based risk. The Company applies 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. The carrying amounts reported in the consolidated financial statements approximate the fair value for cash and cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued liabilities, due to their short-term nature.
Concentration of Risk	Concentration of Risk—Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash, short-term investments, and trade accounts receivable. The Company invests its excess cash in money market funds, certificates of deposit, commercial paper, U.S. treasury securities, U.S. agency securities, and corporate debt securities with major financial institutions. Management believes that the financial institutions that hold the Company’s investments are financially sound and, accordingly, are subject to minimal credit risk.
Income Taxes	Income Taxes—The Company accounts 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 the Company’s consolidated 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 that is more likely than not to be realized. The Company recognizes interest and penalties related to unrecognized tax benefits within the income tax expense line in the consolidated statement of operations
Net Loss Per Share	Net Loss Per Share—The Company’s basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding for the period. The diluted net loss per share is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, options to purchase common stock, common stock reserved for issuance, restricted stock units, convertible debt, and shares issuable pursuant to the ESPP are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share as their effect is antidilutive
Recent Accounting Pronouncements	Recently Issued Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which requires lessees to put most leases on their balance sheets but recognize the expenses on their income statements in a manner similar to current practice. ASU 2016-02 states that a lessee would recognize a lease liability for the obligation to make lease payments and a right-to-use asset for the right to use the underlying asset for the lease term. ASU 2016-02 is effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2018. The Company plans to adopt this new standard using the modified retrospective approach and will not restate comparative periods in the first quarter of fiscal 2020. The Company is also finalizing the incremental borrowing rate for each arrangement. The Company is finalizing the impact of the new standard which will result in the recording of a right of use asset and lease liability on the consolidated balance sheet derived from the present value of future minimum lease payments which are disclosed in Note 10. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which amends guidance on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities. The updated guidance requires that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down. The measurement of credit losses for newly recognized financial assets and subsequent changes in the allowance for credit losses are recorded in the statement of income. The update to the standard will be effective for the Company in the fiscal year beginning April 1, 2020; early adoption is permitted in the fiscal year beginning April 1, 2019. The Company is currently evaluating the effect the standard will have on its consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which eliminates Step 2 from the goodwill impairment test. This standard is effective for goodwill impairment tests performed by the Company in the fiscal year beginning April 1, 2020; early adoption is permitted. The Company has not yet adopted ASU 2017-04 and does not believe that this standard will have a material impact on its consolidated financial statements or disclosures. In March 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract; Disclosures for Implementation Costs Incurred for Internal-Use Software and Cloud Computing Arrangements, which aligns the accounting for implementation costs incurred in a hosting arrangement that is a service contract with the accounting for implementation costs incurred to develop or obtain internal-use software under ASC 350-40, in order to determine which costs to capitalize and recognize as an asset. ASU 2018-15 is effective for annual reporting periods, and interim periods within those years, beginning after December 15, 2019, and can be applied either prospectively to implementation costs incurred after the date of adoption or retrospectively to all arrangements. The Company is currently evaluating the effect the standard will have on its consolidated financial statements. The Company plans to early adopt this standard in the first quarter of fiscal 2020 on a prospective basis and does not believe that this standard will have a material impact on its consolidated financial statements and disclosures. In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Non-Employee Share Based Payment Accounting (“ASU 2018-07”), with an intent to reduce cost and complexity and to improve financial reporting for share-based payments issued to non-employees. The amendments in ASU 2018-07 provide for the simplification of the measurement of share-based payment transactions for acquiring goods and services from non-employees. Currently, the accounting requirements for nonemployee and employee share-based payment transactions are significantly different. This standard expands the scope of Topic 718 to include share-based payments issued to nonemployees for goods or services, aligning the accounting for share-based payments to nonemployees and employees. ASU 2018-07 is effective for annual reporting periods beginning after December 15, 2018, including interim periods within those periods, and early adoption is permitted. The Company plans to adopt this new standard in the first quarter of fiscal 2020. The Company does not expect the adoption to have a significant impact on its consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), which amends ASC 820, Fair Value Measurement. ASU 2018-13 modifies the disclosure requirements for fair value measurements by removing, modifying, or adding certain disclosures. The effective date is the first quarter of fiscal year 2021, with early adoption permitted for the removed disclosures and delayed adoption permitted until fiscal year 2021 for the new disclosures. The removed and modified disclosures will be adopted on a retrospective basis and the new disclosures will be adopted on a prospective basis. The Company has not yet adopted ASU 2018-13 and is currently evaluating the effect the standard will have on its consolidated financial statements. Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU 2014-09 regarding ASC 606, amending revenue recognition guidance and requiring more detailed disclosures to enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. ASC 606 also includes Subtopic 340-40, Other Assets and Deferred Costs - Contracts with Customers, which requires the deferral of incremental costs of obtaining a contract with a customer. The Company adopted ASC 606 and its related amendments effective on April 1, 2018 using the modified retrospective method. See Note 4—Revenue Recognition for disclosure on the impact of adopting this standard on the Company’s consolidated financial statements. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash, which requires restricted cash and restricted cash equivalents to be included with cash and cash equivalents in the statements of cash flows. The Company adopted the standard in its fiscal year beginning April 1, 2018. Adoption was applied on a retrospective basis to all periods presented. Aside from conforming to new cash flow presentation and restricted cash disclosure requirements, the standard did not have a material impact on the Company’s consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting, which amends the scope of modification accounting for share-based payment arrangements. The ASU provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting. On April 1, 2018, the Company adopted ASU 2017-09 and the adoption did not have a significant impact on its consolidated financial statements. In March 2018, the FASB issued ASU 2018-05, which amends ASC Topic 740, Income Taxes to conform with SEC Staff Accounting Bulletin (SAB) No. 118, issued in December 2017. The guidance was issued to address the application of GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Cuts and Jobs Act. See Note 12—Income Taxes.