Description of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Description of Business	Description of Business—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 software-as-a-service provider of products that allow users to monitor software and infrastructure performance and measure end user activities across desktop and mobile devices with applications deployed in the cloud or in a data center. New Relic’s products and platform capabilities enable software developers, IT operations, and business users to better operate their digital business.
Basis of Presentation	Basis of Presentation —These unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the fiscal year ended March 31, 2018, as filed with the SEC on May 11, 2018 (the “Annual Report”). Except for updates to the Company’s accounting policies related to the adoption of Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers regarding Accounting Standards Codification (“ASC”) Topic 606 (“ASC 606”), there have been no changes to the Company’s significant accounting policies described in the Annual Report that have had a material impact on its condensed consolidated financial statements and related notes. Effective April 1, 2018, the Company adopted the requirements of ASC 606. The comparative information has not been restated and continues to be reported under the accounting standards in effect for the period presented, ASC 605, Revenue Recognition (“ASC 605”). In the opinion of management, the unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, comprehensive loss and cash flows for the interim period, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year ending March 31, 2019. The condensed consolidated balance sheet as of March 31, 2018 included herein was derived from the audited financial statements as of that date.
Use of Estimates	Use of Estimates—The preparation of the Company’s condensed 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 condensed 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 condensed consolidated financial statements; therefore, actual results could differ from management’s estimates.
Concentration of Risk	Concentration of Risk—There was one customer that represented more than 10% of the Company’s accounts receivable balance as of December 31, 2018 and no customers that represented more than 10% of the Company’s accounts receivable balance as of March 31, 2018. There were no customers that individually exceeded 10% of the Company’s revenue during the three and nine months ended December 31, 2018 or 2017.
Recent Accounting Pronouncements	Recent 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 condensed consolidated financial statements. 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 with optional practical expedients in the first quarter of fiscal 2020. The Company continues to evaluate the accounting, transition, and disclosure requirements of this standard and cannot currently estimate the financial statement impact of adoption. 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 condensed 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 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 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 condensed 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 11—Income Taxes. 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. 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 condensed 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.
Revenue Recognition	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 three and nine months ended December 31, 2018, which was included in the deferred revenue balances at the beginning of the period, was $90.5 million and $169.3 million, respectively. The satisfaction of performance obligations typically lags behind payments received under the new standard, 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 three and nine months ended December 31, 2018. Deferred Commission Costs (Contract Acquisition Costs) In connection with the adoption of ASC 340-40, the Company is required to capitalize certain contract acquisition costs primarily consisting of commissions. 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 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 this standard was recognized on April 1, 2018. See below for the impact of adopting this standard. The Company recognized the cumulative effect of applying the new revenue standard 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.” 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 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.