Mimecast (MIME) 10-K 29 May 19 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Mar. 31, 2019	May 15, 2019	Sep. 28, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Trading Symbol	MIME
Entity Registrant Name	Mimecast Ltd
Entity Central Index Key	0001644675
Current Fiscal Year End Date	--03-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 1,864,042,783
Entity Common Stock, Shares Outstanding		61,345,165

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Current assets
Cash and cash equivalents	$ 137,576	$ 78,339
Short-term investments	35,941	58,871
Accounts receivable, net	80,953	65,392
Deferred contract costs, net	8,140
Prepaid expenses and other current assets	25,871	15,302
Total current assets	288,481	217,904
Property and equipment, net	94,202	123,822
Intangible assets, net	30,623	9,819
Goodwill	107,575	5,631
Deferred contract costs, net of current portion	28,250
Other assets	5,156	1,222
Total assets	554,287	358,398
Current liabilities
Accounts payable	9,457	6,052
Accrued expenses and other current liabilities	44,309	33,878
Deferred revenue	163,102	123,057
Current portion of capital lease obligations	844	1,125
Current portion of long-term debt	4,059
Total current liabilities	221,771	164,112
Deferred revenue, net of current portion	12,472	18,045
Long-term capital lease obligations	1,381	2,390
Long-term debt	92,797
Construction financing lease obligations	36,650	67,205
Other non-current liabilities	15,581	4,954
Total liabilities	380,652	256,706
Commitments and contingencies (Note 12)
Shareholders' equity
Ordinary shares, $0.012 par value, 300,000,000 shares authorized; 61,158,051 and 58,949,644 shares issued and outstanding as of March 31, 2019 and March 31, 2018, respectively	734	707
Additional paid-in capital	263,388	212,839
Accumulated deficit	(83,632)	(106,507)
Accumulated other comprehensive loss	(6,855)	(5,347)
Total shareholders' equity	173,635	101,692
Total liabilities and shareholders' equity	$ 554,287	$ 358,398

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2019	Mar. 31, 2018
Statement Of Financial Position [Abstract]
Ordinary shares, par value	$ 0.012	$ 0.012
Ordinary shares, authorized	300,000,000	300,000,000
Ordinary shares, issued	61,158,051	58,949,644
Ordinary shares, outstanding	61,158,051	58,949,644

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenue	$ 340,377,000	$ 261,897,000	$ 186,563,000
Cost of revenue	90,874,000	69,699,000	50,314,000
Gross profit	249,503,000	192,198,000	136,249,000
Operating expenses
Research and development	57,939,000	38,373,000	22,593,000
Sales and marketing	139,194,000	121,246,000	96,154,000
General and administrative	53,759,000	36,989,000	27,875,000
Impairment of long-lived assets	0	1,712,000	0
Restructuring	(170,000)	832,000
Total operating expenses	250,722,000	199,152,000	146,622,000
Loss from operations	(1,219,000)	(6,954,000)	(10,373,000)
Other income (expense)
Interest income	2,515,000	1,310,000	510,000
Interest expense	(5,940,000)	(598,000)	(268,000)
Foreign exchange (expense) income and other, net	(356,000)	(3,439,000)	6,892,000
Total other income (expense), net	(3,781,000)	(2,727,000)	7,134,000
Loss before income taxes	(5,000,000)	(9,681,000)	(3,239,000)
Provision for income taxes	2,001,000	2,705,000	2,202,000
Net loss	$ (7,001,000)	$ (12,386,000)	$ (5,441,000)
Net loss per ordinary share
Basic and diluted	$ (0.12)	$ (0.22)	$ (0.10)
Weighted-average number of ordinary shares outstanding
Basic and diluted	59,960	57,269	54,810

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (7,001)	$ (12,386)	$ (5,441)
Other comprehensive (loss) income:
Net unrealized gains (losses) on investments, net of tax	117	40	(129)
Change in foreign currency translation adjustment	(1,625)	2,839	(5,247)
Reclassification of cumulative translation adjustment to net loss upon liquidation of subsidiaries, net of tax		188
Total other comprehensive (loss) income	(1,508)	3,067	(5,376)
Comprehensive loss	$ (8,509)	$ (9,319)	$ (10,817)

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Ordinary Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning balance at Mar. 31, 2016	$ 78,074	$ 651	$ 169,037	$ (88,576)	$ (3,038)
Beginning balance, Shares at Mar. 31, 2016		54,217,000
Net loss	(5,441)			(5,441)
Foreign currency translation adjustment	(5,247)				(5,247)
Unrealized gain (losses) on investments	(129)				(129)
Issuance of ordinary shares upon exercise of share options	4,476	$ 20	4,456
Issuance of ordinary shares upon exercise of share options, Shares		1,657,000
Share-based compensation	10,259		10,259
Vesting of restricted share units (RSUs)		28,000
Ending balance at Mar. 31, 2017	81,992	$ 671	183,752	(94,017)	(8,414)
Ending balance, Shares at Mar. 31, 2017		55,902,000
Cumulative effect adjustment | ASU 2016-09 [Member]			104	(104)
Excess tax benefits related to exercise of share options	217		217
Net loss	(12,386)			(12,386)
Foreign currency translation adjustment	3,027				3,027
Unrealized gain (losses) on investments	40				40
Issuance of ordinary shares upon exercise of share options	15,636	$ 36	15,600
Issuance of ordinary shares upon exercise of share options, Shares		2,961,000
Share-based compensation	11,763		11,763
Employee share purchase plan (ESPP) purchase	1,492		1,492
Employee share purchase plan (ESPP) purchase, Shares		67,000
Tax withholdings on issuance of ordinary shares	(89)		(89)
Tax withholdings on issuance of ordinary shares, Shares		(3,000)
Vesting of restricted share units (RSUs)		23,000
Ending balance at Mar. 31, 2018	$ 101,692	$ 707	212,839	(106,507)	(5,347)
Ending balance, Shares at Mar. 31, 2018	58,949,644	58,950,000
Cumulative effect adjustment | ASU 2014-09 [Member]	$ 29,876			29,876
Net loss	(7,001)			(7,001)
Foreign currency translation adjustment	(1,625)				(1,625)
Unrealized gain (losses) on investments	117				117
Issuance of ordinary shares upon exercise of share options	$ 21,353	$ 25	21,328
Issuance of ordinary shares upon exercise of share options, Shares	2,054,813	2,055,000
Share-based compensation	$ 25,929		25,929
Employee share purchase plan (ESPP) purchase	3,633	$ 2	3,631
Employee share purchase plan (ESPP) purchase, Shares		138,000
Vesting of restricted share units (RSUs)		24,000
Tax withholding on ESPP purchases and vesting of RSUs	(339)		(339)
Tax withholding on ESPP purchases and vesting of RSUs, Shares		(9,000)
Ending balance at Mar. 31, 2019	$ 173,635	$ 734	$ 263,388	$ (83,632)	$ (6,855)
Ending balance, Shares at Mar. 31, 2019	61,158,051	61,158,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows	12 Months Ended
	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)
Operating activities
Net loss	$ (7,001,000)	$ (12,386,000)	$ (5,441,000)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	29,953,000	18,960,000	11,881,000
Share-based compensation expense	25,954,000	11,734,000	10,294,000
Amortization of deferred contract costs	6,390,000
Amortization of debt issuance costs	336,000
Impairment of long-lived assets	0	1,712,000	0
Other non-cash items	(400,000)	365,000	128,000
Unrealized currency loss (gain) on foreign denominated transactions	880,000	2,958,000	(6,496,000)
Changes in assets and liabilities:
Accounts receivable	(18,771,000)	(17,935,000)	(11,663,000)
Prepaid expenses and other current assets	(2,046,000)	(5,037,000)	(2,752,000)
Deferred contract costs	(20,219,000)
Other assets	(2,045,000)	33,000	1,861,000
Accounts payable	2,093,000	(104,000)	758,000
Deferred revenue	45,901,000	39,042,000	29,072,000
Accrued expenses and other liabilities	5,210,000	7,070,000	4,872,000
Net cash provided by operating activities	66,235,000	46,412,000	32,514,000
Investing activities
Purchases of investments	(42,856,000)	(76,948,000)	(67,550,000)
Maturities of investments	66,000,000	77,808,000	7,000,000
Purchases of property, equipment and capitalized software	(28,795,000)	(34,498,000)	(18,491,000)
Payments for acquisitions, net of cash acquired	(115,673,000)	(1,381,000)	(5,574,000)
Net cash used in investing activities	(121,324,000)	(35,019,000)	(84,615,000)
Financing activities
Proceeds from issuance of ordinary shares	24,688,000	17,039,000	4,476,000
Payments on debt	(1,875,000)	(1,825,000)	(4,559,000)
Payments on capital lease obligations	(1,275,000)	(1,039,000)	(249,000)
Payments on construction financing lease obligations	(2,301,000)	(1,019,000)
Proceeds from issuance of debt, net of issuance costs	97,748,000
Net cash provided by (used in) financing activities	116,985,000	13,156,000	(332,000)
Effect of foreign exchange rates on cash	(2,659,000)	2,471,000	(2,388,000)
Net increase (decrease) in cash and cash equivalents	59,237,000	27,020,000	(54,821,000)
Cash and cash equivalents at beginning of period	78,339,000	51,319,000	106,140,000
Cash and cash equivalents at end of period	137,576,000	78,339,000	51,319,000
Supplemental disclosure of cash flow information
Cash paid during the period for interest	4,598,000	591,000	211,000
Cash paid during the period for income taxes	3,010,000	2,545,000	2,046,000
Supplemental disclosure of non-cash investing and financing activities
Unpaid purchases of property, equipment and capitalized software	7,634,000	7,977,000	848,000
Property and equipment acquired under capital lease		4,000,000	713,000
Construction costs capitalized under financing lease obligations	27,903,000	$ 70,645,000
Derecognition of building upon completion of construction period	(56,794,000)
Amounts due from seller for acquisitions			$ 600,000
Withholding taxes payable upon RSU vesting	$ 41,000

Organization and Description of

Organization and Description of Business	12 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Organization and Description of Business	1. Organization and Description of Business Mimecast Limited (Mimecast Jersey) is a public limited company organized under the laws of the Bailiwick of Jersey on July 28, 2015. On November 4, 2015, Mimecast Jersey changed its corporate structure whereby it became the holding company of Mimecast Limited (Mimecast UK), a private limited company incorporated in 2003 under the laws of England and Wales, and its wholly-owned subsidiaries by way of a share-for-share exchange in which the shareholders of Mimecast UK exchanged their shares in Mimecast UK for an identical number of shares of the same class in Mimecast Jersey. Upon the exchange, the historical consolidated financial statements of Mimecast UK became the historical consolidated financial statements of Mimecast Jersey. Mimecast Jersey and its subsidiaries (together, the Group, the Company, Mimecast or we) is headquartered in London, England. The principal activity of the Group is the provision of email management services. Mimecast delivers a software-as-a-service (SaaS) enterprise email management service for archiving, continuity, and security. By unifying disparate and fragmented email environments into one holistic solution from the cloud, Mimecast minimizes risk and reduces cost and complexity while providing total end-to-end control of email. Mimecast’s proprietary software platform provides a single system to address key email management issues. Mimecast operates principally in Europe, North America, Africa and Australia. The Company is subject to a number of risks and uncertainties common to companies in similar industries and stages of development including, but not limited to, rapid technological changes, competition from substitute products and services from larger companies, customer concentration, management of international activities, protection of proprietary rights, patent litigation, and dependence on key individuals.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The accompanying consolidated financial statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the consolidated financial statements. The Company believes that a significant accounting policy is one that is both important to the portrayal of the Company’s financial condition and results, and requires management’s most difficult, subjective, or complex judgments, often as the result of the need to make estimates about the effect of matters that are inherently uncertain. Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB). The Company reclassified certain amounts within its consolidated statements of cash flows to conform to current period presentation. The reclassifications include $0.2 million of loss on disposal of fixed assets to other non-cash items and $0.1 million of provision for doubtful accounts to accounts receivable for the year ended March 31, 2018. Additionally, the Company reclassified $5.6 million of unpaid purchases of capitalized software licenses to unpaid purchases of property, equipment and capitalized software within the supplemental disclosure of non-cash investing and financing activities for the year ended March 31, 2018. These reclassifications had no impact on the Company’s previously reported results of operations or its balance sheets. Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the 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 estimates relied upon in preparing these consolidated financial statements include revenue recognition, variable consideration, valuation at fair value of assets acquired or sold, including intangibles, goodwill, tangible assets, and liabilities assumed, amortization periods, expected future cash flows used to evaluate the recoverability of long-lived assets, contingent liabilities, construction financing lease obligations, restructuring liabilities, expensing and capitalization of research and development costs for internal-use software, the determination of the fair value of share-based awards issued, the average period of benefit associated with costs capitalized to obtain revenue contracts and the recoverability of the Company’s net deferred tax assets and related valuation allowance. Although the Company regularly assesses these estimates, actual results could differ materially from these estimates. The Company bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances. Actual results may differ from management’s estimates if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. Changes in estimates are recorded in the period in which they become known. Subsequent Events Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required. See Note 16. Cash, Cash Equivalents and Investments The Company considers all highly liquid instruments purchased with an original maturity date of 90 days or less from the date of purchase to be cash equivalents. Cash and cash equivalents consist of cash on deposit with banks, amounts held in interest-bearing money market funds and investments with maturities of 90 days or less from the date of purchase. Cash equivalents are carried at cost, which approximates their fair market value. Investments not classified as cash equivalents are presented as either short-term or long-term investments based on both their stated maturities as well as the time period the Company intends to hold such securities. The Company determines the appropriate classification of investments at the time of purchase and reevaluates such designation at each balance sheet date. The Company adjusts the cost of investments for amortization of premiums and accretion of discounts to maturity. The Company includes such amortization and accretion in interest income. The Company has classified all of its investments as of March 31, 2019 as available-for-sale pursuant to ASC 320, Investments – Debt Securities The Company reviews investments for other-than-temporary impairment whenever the fair value of an investment is less than the amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. Other-than-temporary impairments of investments are recognized in the consolidated statements of operations if the Company has experienced a credit loss, has the intent to sell the investment, or if it is more likely than not that the Company will be required to sell the investment before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and the duration of the impairment and changes in value subsequent to the end of the period. The aggregate fair value of investments held by the Company in an unrealized loss position for less than twelve months as of March 31, 2019 was $10.0 million. As of March 31, 2019, the Company determined that no other-than-temporary impairments were required to be recognized in the consolidated statements of operations. The following is a summary of cash, cash equivalents and investments as of March 31, 2019 and March 31, 2018: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2019: Cash and cash equivalents due in 90 days or less $ 137,576 $ — $ — $ 137,576 Investments: U.S. treasury securities due in one year or less 1,993 1 — 1,994 Non-U.S. government securities due in one year or less 7,969 12 — 7,981 Corporate securities due in one year or less 25,951 24 (9 ) 25,966 Total investments 35,913 37 (9 ) 35,941 Total cash, cash equivalents and investments $ 173,489 $ 37 $ (9 ) $ 173,517 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2018: Cash and cash equivalents due in 90 days or less $ 78,339 $ — $ — $ 78,339 Investments: U.S. treasury securities due in one year or less 2,995 — (5 ) 2,990 Non-U.S. government securities due in one year or less 5,996 1 (1 ) 5,996 Corporate securities due in one year or less 49,969 8 (92 ) 49,885 Total investments 58,960 9 (98 ) 58,871 Total cash, cash equivalents and investments $ 137,299 $ 9 $ (98 ) $ 137,210 Revenue Recognition Adoption of ASC 606 Effective April 1, 2018, the Company adopted the requirements of ASU No. 2014-09, under the modified retrospective method of transition, which was applied to all customer contracts that were not completed on the effective date of ASC 606. The Company implemented internal controls and key system functionality to enable the preparation of financial information on adoption. The adoption of ASC 606 resulted in changes to the Company’s accounting policies for revenue recognition and related costs previously recognized under ASC 605, Revenue Recognition Revenue Recognition Policy Under ASC 606 the Company recognizes revenue upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. To achieve the core principle of ASC 606, the Company performs the following steps: 1) Identify the contract(s) with a customer; 2) Identify the performance obligations in the contract; 3) Determine the transaction price; 4) Allocate the transaction price to the performance obligations in the contract; and 5) Recognize revenue when (or as) the Company satisfies a performance obligation. The Company derives its revenue from two sources: (1) subscription revenues, which are comprised of subscription fees from customers accessing the Company’s cloud services and from customers purchasing additional support beyond the standard support that is included in the basic subscription fees; and (2) related professional services and other revenue, which consists primarily of certain performance obligations related to set-up, ingestion, consulting and training fees. In the years ended March 31, 2019, 2018 and 2017, subscription revenue made up the substantial majority of the Company’s revenue and professional services and other revenue made up less than 5% of the Company’s revenue. The Company’s subscription arrangements provide customers the right to access the Company’s hosted software applications. Customers do not have the right to take possession of the Company’s software during the hosting arrangement. The Company sells its products and services directly through the Company’s sales force and also indirectly through third-party resellers. In accordance with the provisions of ASC 606, the Company has considered certain factors in determining whether the end-user or the third-party reseller is the customer in arrangements involving resellers. The Company concluded that in the majority of transactions with resellers, the reseller is the customer. In these arrangements, the Company considered that it is the reseller, and not the Company, that has the relationship with the end-user. Specifically, the reseller has the ability to set pricing with the end-user and the credit risk with the end-user is borne by the reseller. Further, the reseller is not obligated to report its transaction price with the end-user to the Company, and in the majority of transactions, the Company is unable to determine the amount paid by the end-user customer to the reseller in these transactions. As a result of such considerations, revenue for these transactions is presented in the accompanying consolidated statements of operations based upon the amount billed to the reseller. For transactions where the Company has determined that the end-user is the ultimate customer, revenue is presented in the accompanying consolidated statements of operations based on the transaction price with the end-user. The Company recognizes subscription and support revenue ratably over the term of the contract, typically one year in duration, beginning on the date the customer is provided access to the Company’s service. For performance obligations related to set-up and ingestion, including implementation assistance and data migration services, respectively, the Company recognizes revenue using output measures of performance that reflect the transfer of promised services to the customer consistent with progress to completion. The Company considers training, consulting, and other professional services contracts as separate performance obligations and recognizes revenue using output measures of performance as services are completed. Amounts that have been invoiced are recorded in accounts receivable and in deferred revenue or revenue, depending on whether the revenue recognition criteria have been met. The Company primarily bills and collects payments from customers for its services in advance on a monthly and annual basis. In some instances, the Company receives non-refundable upfront payments for activities that do not constitute a promise to transfer a service and therefore are considered administrative tasks, not separate performance obligations. The upfront payments are evaluated to determine whether a material right to a discount upon renewal of the subscription exists. When the Company concludes a material right does not exist, the Company recognizes revenue related to the upfront payment over the initial contract term. When the Company concludes a material right does exist, the Company recognizes revenue related to the upfront payment, under the look-through method, over the estimated customer benefit period, which has been determined to be six years. All of the Company’s performance obligations, and associated revenue, are generally transferred to customers over time, with the exception of training, consulting and other professional services, which are generally transferred to the customer at a point in time. Revenue is presented net of any taxes collected from customers. Some of the Company’s contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative standalone selling price basis. The Company determines the standalone selling prices based on the Company’s overall pricing objectives, taking into consideration market conditions and other factors, including the value of the Company’s contracts, the products sold, customer demographics, the Company’s sales channel, and the number and size of users within the Company’s contracts. Deferred revenue primarily consists of billings or payments received in advance of revenue recognition from subscription and other services described above and is recognized as the revenue recognition criteria are met. Deferred revenue that is expected to be recognized during the succeeding twelve-month period is recorded as current deferred revenue and the remaining portion is recorded as non-current in the accompanying consolidated balance sheets. Deferred Cost Policy As part of the Company’s adoption of ASC 606 , the Company capitalizes incremental costs of obtaining revenue contracts, which primarily consist of commissions paid to its sales representatives. The Company amortizes these commissions over six years on a systematic basis, consistent with the pattern of transfer of the goods or services to which the asset relates. Six years represents the estimated benefit period of the customer relationship taking into account factors such as peer estimates of technology lives and customer lives as well as the Company's own historical data. No commissions are paid related to contract renewals. The current and noncurrent portions of deferred commissions are included in deferred contract costs, net, and deferred contract costs, net of current portion, respectively, in the accompanying consolidated balance sheets. Impact of Adoption of ASC 606 The adoption of ASC 606 resulted in a decrease to deferred revenue of $6.0 million and an increase of $23.8 million in deferred contract costs as of April 1, 2018. The Company recorded the deferred tax impact associated with the cumulative effect adjustment of adopting ASC 606 to accumulated deficit with an equal and offsetting adjustment to the Company’s valuation allowance. The decrease to deferred revenue upon adoption was primarily due to a change in the accounting treatment for certain upfront fees that were accounted for as a single unit of account under Legacy GAAP and are accounted for as separate performance obligations under ASC 606. The increase in deferred contract costs was the result of the capitalization of certain commissions that were determined to be incremental costs of obtaining a contract. Under Legacy GAAP, the Company expensed all commission costs as incurred. As a result of the adoption of ASC 606, the Company’s accumulated deficit decreased by $29.9 million as of April 1, 2018, which was the net cumulative impact associated with the capitalization of sales commissions and the adjustment to deferred revenue. The cumulative effect of the changes made to the Company’s April 1, 2018 balance sheet for the adoption of ASC 606 was as follows: Balance as of March 31, 2018 Adjustments Due to Adoption of ASC 606 Balance as of April 1, 2018 Assets Deferred contract costs, net $ — $ 5,494 $ 5,494 Deferred contract costs, net of current portion — 18,339 18,339 Liabilities Deferred revenue 123,057 (517 ) 122,540 Deferred revenue, net of current portion 18,045 (5,526 ) 12,519 Shareholders' equity Accumulated deficit (106,507 ) 29,876 (76,631 ) In accordance with the requirements of ASC 606, the disclosure for the quantitative effect and the significant changes between the reported results under ASC 606 and those that would have been reported under Legacy GAAP on our consolidated statements of operations and balance sheet are as follows: Year ended March 31, 2019 As Reported - ASC 606 Amounts without Adoption of ASC 606 Effect of Change Increase/(Decrease) Income Statement Revenues $ 340,377 $ 338,829 $ 1,548 Operating expenses Sales and marketing (139,194 ) (153,003 ) (13,809 ) Net loss $ (7,001 ) $ (22,358 ) $ 15,357 As of March 31, 2019 As Reported - ASC 606 Balances without Adoption of ASC 606 Effect of Change Increase/(Decrease) Balance Sheet Assets Deferred contract costs, net $ 8,140 $ — $ 8,140 Deferred contract costs, net of current portion 28,250 — 28,250 Liabilities Deferred revenue 163,102 161,746 1,356 Deferred revenue, net of current portion 12,472 21,336 (8,864 ) Shareholders' equity Accumulated deficit (83,632 ) (128,865 ) 45,233 Revenue recognized during the twelve months ended March 31, 2019 from amounts included in deferred revenue at the beginning of the period was approximately $118.7 million. Revenue recognized during the twelve months ended March 31, 2019 from performance obligations satisfied or partially satisfied in previous periods was not material. The adoption of ASC 606 had no impact to net operating cash flows. Contracted revenue as of March 31, 2019 that has not yet been recognized (contracted and not recognized) was $86.0 million, which includes deferred revenue and non-cancellable amounts that will be invoiced and recognized as revenue in future periods and excludes contracts with an original expected length of one year or less. The Company expects 51% of contracted and not recognized revenue to be recognized over the next twelve months, 46% in years two and three, with the remaining balance recognized thereafter. Cost of Revenue Cost of revenue primarily consists of expenses related to supporting and hosting the Company’s product offerings and delivering professional services. These costs include salaries, benefits, incentive compensation and share-based compensation expense related to the management of the Company’s data centers, customer support team and the Company’s professional services team. In addition to these costs, the Company incurs third-party service provider costs such as data center and networking expenses, allocated overhead, amortization of capitalized software and acquired Concentration of Credit Risk and Off-Balance Sheet Risk The Company has no off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments, which potentially subject us to concentrations of credit risk, consist primarily of cash and cash equivalents, investments and accounts receivable. The Company maintains its cash and cash equivalents with major financial institutions of high-credit quality. Although the Company deposits its cash with multiple financial institutions, its deposits, at times, may exceed federally insured limits. Credit risk with respect to accounts receivable is dispersed due to our large number of customers. The Company’s accounts receivable balances are derived from revenue earned from customers primarily located in the United Kingdom, the United States, and South Africa. The Company generally does not require its customers to provide collateral or other security to support accounts receivable. Credit losses historically have not been significant and the Company generally has not experienced any material losses related to receivables from individual customers, or groups of customers. Due to these factors, no additional credit risk beyond amounts provided for collection losses is believed by management to be probable in the Company’s accounts receivable. As of March 31, 2019 and 2018, no individual customer represented more than 10% of our accounts receivable. During the years ended March 31, 2019, 2018 and 2017, no individual customer represented more than 10% of our revenue. The Company's board of directors approved investment policy permits investments in fixed income securities denominated and payable in U.S. dollars including U.S. government and agency securities, non-U.S. government securities, money market instruments, commercial paper, certificates of deposit, corporate bonds and asset-backed securities. The Company diversifies its investment portfolio by investing in multiple types of investment-grade securities across various industries and issuers, limiting the amount invested in individual securities and limiting the average maturity to two years or less. As of March 31, 2019, the Company’s investments consisted primarily of investment-grade fixed income corporate debt securities with maturities ranging from 1 to 7 months, non-U.S. government securities with maturities ranging from 3 to 8 months and U.S. treasury securities with maturities in approximately 5 months. Allowance for Doubtful Accounts The Company makes judgments as to its ability to collect outstanding receivables and provide allowances for the portion of receivables when a loss is reasonably expected to occur. The allowance for doubtful accounts is established to represent the best estimate of the net realizable value of the outstanding accounts receivable. The development of the allowance for doubtful accounts is based on a review of past due amounts, historical write-off and recovery experience, as well as aging trends affecting specific accounts and general operational factors affecting all amounts. In addition, factors are developed utilizing historical trends in bad debts, returns and allowances. The Company considers current economic trends when evaluating the adequacy of the allowance for doubtful accounts. If circumstances relating to specific customers change or unanticipated changes occur in the general business environment, the Company’s estimates of the recoverability of receivables could be further adjusted. For the years ended March 31, 2019, 2018 and 2017, bad debt expense was $0.2 million, $0.2 million and $0.1 million, respectively. The allowance for doubtful accounts as of March 31, 2019 and 2018 was not material. Property and Equipment Property and equipment are stated at cost, and are depreciated using the straight-line method over the estimated useful life of the assets. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the related asset. Property and equipment acquired under capital leases is amortized over the lease term or, in circumstances where ownership is transferred by the end of the lease or there is a bargain purchase option, over the useful life that would be assigned if the asset were owned. Upon retirement or sale, the cost of assets disposed of, and the related accumulated depreciation, are removed from the accounts, and any resulting gain or loss is included in the determination of net loss in the period of retirement or sale. The estimated useful lives of the Company’s property and equipment are as follows: Estimated Useful Life Buildings and building improvements (1) 10 Computer equipment 3 to 5 Leasehold improvements Lesser of asset life or lease term Furniture and fixtures 5 Office equipment 3 (1) Building and building improvement assets under build-to-suit accounting are depreciated over their useful lives during the lease period. Expenditures for maintenance and repairs are charged to expense as incurred, whereas major betterments are capitalized as additions to property and equipment. Business Combinations In accordance with ASC 805, 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 value of the assets acquired and the liabilities assumed and represents the expected future economic benefits arising from other assets acquired that are not individually identified and separately recognized. While the Company uses its best estimates and assumptions as 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. Assumptions may be incomplete or inaccurate, and unanticipated events or circumstances may occur, which may affect the accuracy or validity of such assumptions, estimates or actual results. 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 it 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 consolidated statements of operations. Goodwill and acquired intangible assets Goodwill is not amortized, but is evaluated for impairment annually, or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The Company has determined that there is a single reporting unit for the purpose of conducting this goodwill impairment assessment. For purposes of assessing potential impairment, the Company estimates the fair value of the reporting unit, based on the Company’s market capitalization, and compares this amount to the carrying value of the reporting unit. If the Company determines that the carrying value of the reporting unit exceeds its fair value, an impairment charge would be required. The annual goodwill impairment test is performed as of January 1 st Intangible assets acquired in a business combination are recorded at their estimated fair values at the date of acquisition. The Company amortizes acquired definite-lived intangible assets over their estimated useful lives based on the pattern of consumption of the economic benefits or, if that pattern cannot be readily determined, on a straight-line basis. Impairment of Long-Lived Assets The Company reviews long-lived assets, including property and equipment and definite-lived intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. During this review, the Company re-evaluates the significant assumptions used in determining the original cost and estimated lives of long-lived assets. Although the assumptions may vary from asset to asset, they generally include operating results, changes in the use of the asset, cash flows, and other indicators of value. Management then determines whether the remaining useful life continues to be appropriate, or whether there has been an impairment of long-lived assets based primarily upon whether expected future undiscounted cash flows are sufficient to support the recoverability of these assets. Recoverability of these assets is measured by comparison of the carrying amount of the asset to the future undiscounted cash flows the asset is expected to generate. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. For the years ended March 31, 2019 and 2017, the Company did not identify any impairment of its long-lived assets. For the year ended March 31, 2018, the Company recorded an i Fair Value Measurements ASC 820, Fair Value Measurements and Disclosures, ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants based on the highest and best use of the asset or liability. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The Company uses valuation techniques to measure fair value that maximize the use of observable inputs and minimize the use of unobservable inputs. These inputs are prioritized as follows: • Level 1 inputs—Unadjusted observable quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 inputs—Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. • Level 3 inputs—Unobservable inputs for determining the fair values of assets or liabilities that reflect an entity’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company evaluates assets and liabilities subject to fair value measurements on a recurring and nonrecurring basis to determine the appropriate level to classify them for each reporting period. The Company measures eligible assets and liabilities at fair value, with changes in value recognized in earnings. Fair value treatment may be elected either upon initial recognition of an eligible asset or liability or, for an existing asset or liability, if an event triggers a new basis of accounting. The Company did not elect to remeasure any of its existing financial assets or liabilities, and did not elect the fair value option for any financial assets and liabilities transacted in the years ended March 31, 2019, 2018 and 2017. Software Development Costs Costs incurred to develop software applications used in the Company’s SaaS platform consist of certain direct costs of materials and services incurred in developing or obtaining internal-use computer software, and payroll and payroll-related costs for employees who are directly associated with, and who devote time to, the project. These costs generally consist of internal labor during configuration, coding, and testing activities. Research and development costs incurred during the preliminary project stage or costs incurred for data conversion activities, training, maintenance and general and administrative or overhead costs are expensed as incurred. Once an application has reached the development stage, internal and external costs, if direct and incremental, are capitalized until the application is substantially complete and ready for its intended use. Qualified costs incurred during the operating stage of the Company’s software applications relating to upgrades and enhancements are capitalized to the extent it is probable that they will result in added functionality, while costs incurred for maintenance of, and minor upgrades and enhancements to, internal-use software are expensed as incurred. During the years ended March 31, 2019, 2018 and 2017, the Company believes the substantial majority of its development efforts were either in the preliminary project stage of development or in the operation stage (post-implementation), and accordingly, no costs have been capitalized during these periods. These costs are included in the accompanying con

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Components	3. Balance Sheet Components Prepaid expenses and other current assets consists of the following: As of March 31, 2019 2018 Prepaid expenses $ 11,259 $ 10,766 Lease incentive due from landlord 8,900 — Research and development investment tax credits 3,862 3,353 Other current assets 1,850 1,183 Total prepaid expenses and other current assets $ 25,871 $ 15,302 Property and equipment, net, consists of the following: As of March 31, 2019 2018 Building and building improvements (1) $ 47,001 $ 75,165 Computer equipment (2) 112,277 102,821 Leasehold improvements 8,166 6,504 Furniture and fixtures 4,590 4,187 Office equipment 1,345 1,172 173,379 189,849 Less: Accumulated depreciation and amortization (1) (2) (79,177 ) (66,027 ) Property and equipment, net $ 94,202 $ 123,822 (1 ) As of March 31, 2019 2018 U.S. build-to-suit facility $ 47,001 $ 43,925 U.K. build-to-suit facility — 31,240 Less: Accumulated depreciation (5,164 ) (753 ) $ 41,837 $ 74,412 As of March 31, 2019 and 2018, the U.S. build-to-suit facility includes company-funded building improvements of $5.2 million and $4.5 million, respectively. In March 2019, the Company derecognized the U.K. build-to-suit facility upon substantial completion of construction (2) Includes property and equipment acquired under capital leases: As of March 31, 2019 2018 Computer equipment $ 4,754 $ 4,713 Less: Accumulated amortization (2,228 ) (990 ) $ 2,526 $ 3,723 Depreciation and amortization expense was $25.2 million, $17.5 million, and $11.8 million for the years ended March 31, 2019, 2018 and 2017, respectively. Depreciation and amortization expense in the years ended March 31, 2019, 2018 and 2017 included $1.2 million, $0.9 million and $0.1 million related to property and equipment acquired under capital leases. Accrued expenses and other current liabilities consists of the following: As of March 31, 2019 2018 Accrued payroll and related benefits $ 21,198 $ 15,325 Accrued taxes payable 5,305 4,029 Construction financing lease obligation 2,670 2,421 Restructuring liability 49 851 Other accrued expenses 15,087 11,252 Total accrued expenses and other current liabilities $ 44,309 $ 33,878 Other non-current liabilities consists of the following: As of March 31, 2019 2018 Deferred rent $ 10,218 $ 840 Restructuring liability — 74 Other non-current liabilities 5,363 4,040 Total other non-current liabilities $ 15,581 $ 4,954

Restructuring

Restructuring	12 Months Ended
	Mar. 31, 2019
Restructuring And Related Activities [Abstract]
Restructuring	4. Restructuring In the fourth quarter of fiscal 2018, the Company ceased use of its Watertown, MA corporate office space and recorded a restructuring charge of $0.8 million. The fair value of the restructuring liability at the cease-use date of $1.1 million was determined by discounting estimated future cash flows, which consisted of remaining lease rentals and estimated sublease rentals that could be reasonably obtained for the property and was adjusted for the effects of deferred rent liabilities recognized under the lease of $0.3 million. The Company’s estimate of sublease rentals was based on a sublease agreement executed in the first quarter of fiscal 2019. In the second quarter of fiscal 2019, the Company recorded a revision to restructuring expense of $0.2 million related to the exit of its Watertown, Massachusetts corporate office space. The restructuring liability and any future changes in the estimate will be recorded in Restructuring in the consolidated statements of operations. The fair value measurement is classified within Level 3 of the fair value hierarchy wherein fair value is estimated using significant unobservable inputs

Acquisitions

Acquisitions	12 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Acquisitions	5. Acquisitions Solebit LABs Ltd. On July 31, 2018, the Company entered into a share purchase agreement (the Purchase Agreement) pursuant to which it acquired Solebit LABS Ltd. (Solebit), a company organized under the laws of the State of Israel, that provides security software. Solebit’s technology enhances security for the Company’s customers and adds to its ability to detect and prevent cyber-attacks, zero day threats and malware across email and the web in real time. This acquisition further enhances the Company’s cyber resilience platform architecture. Prior to the closing of the acquisition, the Company held an ownership interest in Solebit of approximately 1.5%. Upon completion of the acquisition, the Company recognized a gain of $0.3 million recorded in foreign exchange (expense) income and other, net, within the consolidated statement of operations for the remeasurement of its previously held ownership interest to fair value, which was $0.8 million. The total preliminary purchase price of $96.5 million included cash payments of approximately $95.7 million, inclusive of $8.4 million in purchase price held in escrow. The escrow is being held in respect of claims for indemnification for one year from the purchase date. The preliminary purchase price, cash payments and purchase price allocation are subject to finalization of amounts due from the seller for the one-year indemnification period adjustments and potential working capital adjustments. The Company expects to finalize the purchase price within the required one-year measurement period. The acquisition of Solebit has been accounted for as a business combination and, in accordance with ASC 805, the Company has recorded the assets acquired and liabilities assumed at their respective fair values as of the acquisition date. The following table summarizes the preliminary purchase price allocation as of March 31, 2019 (in thousands): Preliminary purchase consideration: Total cash paid, net of acquired cash $ 85,258 Cash and cash equivalents acquired 10,410 Fair value of previously held asset 828 Total preliminary purchase price consideration $ 96,496 Fair value of assets acquired and liabilities assumed: Cash and cash equivalents $ 10,410 Prepaid expenses and other current assets 76 Intangible assets 16,964 Goodwill 74,469 Total assets acquired 101,919 Accounts payable (18 ) Accrued expenses and other current liabilities (2,345 ) Deferred revenue (663 ) Other non-current liabilities (2,397 ) Total fair value of assets acquired and liabilities assumed $ 96,496 In the year ended March 31, 2019, acquisition-related expenses were $1.0 million. Acquisition-related expenses have been included primarily in general and administrative expenses in the consolidated statements of operations. The operating results of Solebit are included in the consolidated statements of operations beginning on the acquisition date. The significant intangible assets identified in the preliminary purchase price allocation discussed above include developed technology and customer relationships, which are amortized over their respective useful lives on a straight-line basis when the pattern in which their economic benefits will be consumed cannot be reliably determined. To value the developed technology asset, the Company utilized the income approach, specifically a discounted cash-flow method known as the multi-period excess earnings method. Customer relationships represent the underlying relationships with certain customers to provide ongoing services for products sold. The Company utilized the income approach, specifically the distribution method, a subset of the excess-earnings method to value the customer relationships. A portion of the preliminary purchase price has been allocated to intangible assets and goodwill, respectively, and is reflected in the tables above. The fair value of the assets acquired and liabilities assumed is less than the preliminary purchase price, resulting in the recognition of goodwill. The goodwill reflects the value of the synergies we expect to realize and the assembled workforce and is not deductible for tax purposes. The preliminary purchase price has been allocated to the tangible and intangible assets acquired and liabilities assumed based upon the respective estimates of fair value as of the date of the acquisition, which remains preliminary, and using assumptions that the Company’s management believes are reasonable given the information then available. The final allocation of the purchase price may differ materially from the information presented in these consolidated financial statements. Any changes to the preliminary estimates of the fair value of the assets acquired and liabilities assumed during the measurement period will be recorded as adjustments to those assets and liabilities and residual amounts will be allocated to goodwill. The following table presents the estimated fair values and useful lives of the identifiable intangible assets acquired: Amount (in thousands) Estimated Useful Life (in years) Developed technology $ 16,689 10 Customer relationships 235 7 Trade names 40 1 Total identifiable intangible assets $ 16,964 Pro Forma Financial Information (unaudited) The following unaudited pro forma information presents the combined results of operations of the Company and Solebit for the years ended March 31, 2019 and 2018 as if the acquisition of Solebit had been completed on April 1, 2017. These pro forma financial results have been prepared for comparative purposes only and include certain adjustments that reflect pro forma results of operations such as fair value adjustments (step-downs) for deferred revenue, increased amortization for the fair value of acquired intangible assets and adjustments to eliminate transaction costs incurred by the Company and Solebit. The unaudited pro forma results do not reflect any operating efficiencies or potential cost savings which may result from the consolidation of the operations of the Company and Solebit. Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of the results of operations that would have been achieved had the acquisition occurred as of April 1, 2017, nor are they intended to represent or be indicative of future results of operations (in thousands, except per share amounts): Year ended March 31, 2019 2018 Revenue $ 340,824 $ 262,773 Net loss (7,729 ) (17,359 ) Basic net loss per share $ (0.13 ) $ (0.30 ) Diluted net loss per share $ (0.13 ) $ (0.30 ) Weighted average number of ordinary shares outstanding Basic and diluted 59,960 57,269 Ataata On July 9, 2018, the Company acquired ATAATA, Inc. (Ataata), a privately-owned company based in the United States, for cash consideration of approximately $23.2 million, net of cash acquired of $1.9 million. Ataata is a cybersecurity training and awareness platform designed to reduce human error in the workplace and help enable organizations to become more secure by changing the security culture of their employees. The acquisition will allow customers to measure cyber risk training effectiveness by converting behavior observations into actionable risk metrics for security professionals. The addition of security awareness training and risk scoring and analysis strengthens the Company’s cyber resilience for email capabilities. The acquisition of Ataata has been accounted for as a business combination and, in accordance with ASC 805, the Company has recorded the assets acquired and liabilities assumed at their respective fair values as of the acquisition date. The preliminary purchase price allocation primarily consisted of $1.5 million of identifiable intangible assets and approximately $22.6 million of goodwill that is not deductible for tax purposes. The identifiable intangible assets primarily include developed technology of $1.4 million and customer relationships of $0.1 million, with estimated useful lives of ten and six years, respectively. The goodwill balance is primarily attributed to the expanded market opportunities when combining Ataata's awareness training technology with the Company’s other offerings. The preliminary purchase price, cash payments and purchase price allocation are subject to finalization of amounts due from the seller for the one-year indemnification period adjustments and potential working capital adjustments. In the year ended March 31, 2019, acquisition-related expenses were $0.5 million. Acquisition-related expenses have been included primarily in general and administrative expenses in the consolidated statements of operations. The operating results of Ataata are included in the consolidated statements of operations beginning on the acquisition date. The Company has not presented pro forma results of operations for the Ataata acquisition because it is not material to the Company's consolidated results of operations, financial position, or cash flows. Simply Migrate On January 25, 2019, the Company acquired Simply Migrate Ltd., an innovative provider of archive data migration technology, . With this acquisition, the Company expands its migration services with a rich portfolio of connectors, combined with a deeper experience in helping organizations get out of the business of managing expensive, unreliable legacy archives so they can move to a next-generation data protection strategy in the Mimecast cloud. This helps enable the Company to reduce costs, safeguard its intellectual property, preserve institutional memory, accelerate e-discovery and achieve compliance The acquisition of Simply Migrate has been accounted for as a business combination and, in accordance with ASC 805, the Company has recorded the assets acquired and liabilities assumed at their respective fair values as of the acquisition date. The preliminary purchase price allocation primarily consisted of $3.3 million of identifiable intangible assets, specifically developed technology, with an estimated useful life of eight years and approximately $4.3 million of goodwill that is not deductible for tax purposes. The goodwill balance is primarily attributed to the expanded market opportunities when combining Simply Mirgate's archive data migration technology In the year ended March 31, 2019, acquisition-related expenses were $0.6 million. Acquisition-related expenses have been included primarily in general and administrative expenses in the consolidated statements of operations. The operating results of Simply Migrate are included in the consolidated statements of operations beginning on the acquisition date. The Company has not presented pro forma results of operations for the Simply Migrate acquisition because it is not material to the Company's consolidated results of operations, financial position, or cash flows.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Mar. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	6. Goodwill and Intangible Assets The following table reflects goodwill activity in each of the periods presented: Year ended March 31, 2019 2018 Beginning balance $ 5,631 $ 5,363 Goodwill acquired 101,381 226 Effect of foreign exchange rates 563 42 Ending balance $ 107,575 $ 5,631 Purchased intangible assets consist of the following: Weighted- Average March 31, 2019 Remaining Gross Net Useful Life Carrying Accumulated Carrying (in years) Value Amortization Value Developed technology 9 $ 23,577 $ (1,707 ) $ 21,870 Customer relationships 6 455 (73 ) 382 Trade names 1 56 (34 ) 22 Capitalized software (1) 3 12,431 (4,082 ) 8,349 $ 36,519 $ (5,896 ) $ 30,623 Weighted- Average March 31, 2018 Remaining Gross Net Useful Life Carrying Accumulated Carrying (in years) Value Amortization Value Developed technology 9 1,546 (213 ) 1,333 Customer relationships 6 108 (21 ) 87 Capitalized software 3 9,171 (1,329 ) 7,842 10,825 (1,563 ) 9,262 In-process research and development (2) 557 — 557 $ 11,382 $ (1,563 ) $ 9,819 (1) Includes $0.4 million of costs capitalized related to video production costs. See Note 2 for further information. (2) In-process research and development assets were placed in service in the year ended March 31, 2019. The Company recorded amortization expense of $4.8 million, $1.5 million and $0.1 million for the years ended March 31, 2019, 2018 and 2017, respectively. Amortization relating to developed technology and capitalized software was recorded within cost of revenue and amortization of customer relationships and trade names was recorded within sales and marketing expenses. Future estimated amortization expense of intangible assets as of March 31, 2019 is as follows: Purchased Intangible Capitalized Assets Software 2020 $ 2,582 $ 3,522 2021 2,560 2,790 2022 2,560 1,420 2023 2,560 528 Thereafter 12,012 89 Total $ 22,274 $ 8,349

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurement	7. Fair Value Measurement The Company’s financial instruments include cash, cash equivalents, investments, accounts receivable, accounts payable, accrued expenses, and borrowings under the Company’s long-term debt arrangements The Company has evaluated the estimated fair value of financial instruments using available market information. The use of different market assumptions and/or estimation methodologies could have a significant effect on the estimated fair value amounts. Fair values determined using “Level 1 inputs” utilize unadjusted quoted prices in active markets for identical assets or liabilities that we have the ability to access. Fair values determined using "Level 2 Inputs" utilize quoted prices that are directly or indirectly observable. Fair values determined using “Level 3 inputs” utilize unobservable inputs for determining fair values of assets or liabilities that reflect an entity's own assumptions in pricing assets or liabilities. As of March 31, 2019 and 2018, the Company did not have any assets or liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3), other than the restructuring liability disclosed in Note 4. The following table summarizes financial assets measured and recorded at fair value on a recurring basis in the accompanying consolidated balance sheets as of March 31, 2019 and 2018, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: March 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs) Significant Other Observable Inputs (Level 2 Inputs) Total Assets: Money market funds $ 8,348 $ — $ 8,348 U.S. treasury securities — 1,994 1,994 Non-U.S. government securities — 7,981 7,981 Corporate securities — 25,966 25,966 Total assets $ 8,348 $ 35,941 $ 44,289 March 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs) Significant Other Observable Inputs (Level 2 Inputs) Total Assets: Money market funds $ 10,143 $ — $ 10,143 U.S. treasury securities — 2,990 2,990 Non-U.S. government securities — 5,996 5,996 Corporate securities — 49,885 49,885 Total assets $ 10,143 $ 58,871 $ 69,014

Debt

Debt	12 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt	8. Debt On July 23, 2018, the Company entered into that certain credit agreement (the Credit Agreement), dated as of July 23, 2018 by and among the Company, certain of the Company’s subsidiaries party thereto, as guarantors, certain financial institutions party thereto from time to time, as lenders, and JPMorgan Chase Bank, N.A., as administrative agent (the Administrative Agent). The Credit Agreement provided the Company with a $100.0 million senior secured term loan (the Term Loan) and a $50.0 million senior secured revolving credit facility (the Revolving Facility, and together with the Term Loan, the Credit Facility). The proceeds of the Credit Facility, net of $2.3 million of debt issuance costs, are available to fund working capital and for other corporate purposes, including to finance permitted acquisitions and investments. Interest under the Credit Facility accrues at a rate between LIBOR plus 1.375% and LIBOR plus 1.875%, based on the Company’s ratio of indebtedness to earnings before interest, taxes, depreciation, amortization and certain other adjustments (Consolidated EBITDA). Based on this ratio, the current interest rate as of March 31, 2019 under the Credit Facility is LIBOR plus 1.625%. The term of the Credit Facility is five years, maturing on July 23, 2023. At the time the Company entered into the Credit Agreement, there was no outstanding debt. The Credit Agreement has financial covenants that require the Company to maintain a Consolidated Secured Leverage Ratio (as defined in the Credit Agreement), commencing on September 30, 2018, of not more than 3.00 to 1.00 for the four consecutive fiscal quarter period ending on the last day of each fiscal quarter (the Reference Period), with a step-up to 3.50 to 1.00 for any four-quarter period in which the Company consummates a permitted acquisition having an aggregate purchase price in excess of $25.0 million. The Company must also maintain a Consolidated Interest Expense Ratio (as defined in the Credit Agreement) of 3.00 to 1.00 commencing on September 30, 2018 and for each Reference Period thereafter. The Company was in compliance with all covenants as of March 31, 2019. The Company allocated debt issuance costs for the Credit Facility on a pro-rata basis between the Term Loan and Revolving Facility. The debt issuance costs on the Term Loan are recorded as a reduction of debt and are amortized and recognized as additional interest expense over the life of the debt instrument using the effective interest method. The debt issuance costs on the Revolving Facility are recorded in other assets and are amortized and recognized as additional interest expense over the life of the Revolving Facility on a straight-line basis. As of March 31, 2019, the balance of debt issuance costs recorded as a reduction of debt was $1.3 million and the balance of debt issuance costs recorded in other assets was $0.6 million. All obligations under the Credit Agreement are unconditionally guaranteed by all of the Company’s material direct and indirect subsidiaries organized under the laws of the United States, the United Kingdom, the Bailiwick of Jersey, and other jurisdictions agreed to by the Company and the Administrative Agent, with certain exceptions. These guarantees are secured by substantially all of the present and future property and assets of the guarantors, with certain exclusions. As of March 31, 2019, the Company had $98.1 million outstanding on the Term Loan and had no outstanding borrowings under the Revolving Facility. Total availability under the Revolving Facility is reduced by outstanding letters of credit of $3.9 million. As of March 31, 2019, total availability under the Revolving Facility was $46.1 million. Future minimum principal payment obligations under the Term Loan are as follows: Year Ending March 31, Debt 2020 $ 4,375 2021 6,875 2022 9,375 2023 10,000 2024 67,500 Total minimum debt payments $ 98,125 Less: Debt issuance costs $ (1,269 ) Less: Current portion of long-term debt $ (4,059 ) Long-term debt $ 92,797

Related Party Transactions

Related Party Transactions	12 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions	9 . Related Party Transactions Certain of the Company’s shareholders and certain companies affiliated with our directors and executive officers were also customers of the Company during the periods included in the consolidated financial statements. Revenue recognized during the years ended March 31, 2019, 2018 and 2017 and accounts receivable outstanding as of March 31, 2019 and 2018 related to these transactions was not material.

Shareholders_ Equity

Shareholders’ Equity	12 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Shareholders’ Equity	10. Shareholders’ Equity As of March 31, 2019, the following ordinary shares were reserved for future issuance under the 2015 Plan, Historical Plans and ESPP (as defined below in Note 11): As of March 31, 2019 Options outstanding under share option plans 6,208,964 Unvested RSUs 549,853 Options and awards available for future grant under the 2015 Plan 9,138,803 Shares reserved for issuance under ESPP 905,114 Total authorized ordinary shares reserved for future issuance 16,802,734

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	11. Share-Based Compensation As of March 31, 2019, the Company has four share-based compensation plans and an employee share purchase plan. Prior to the Company’s initial public offering (IPO) in November 2015, the Company granted share-based awards under three share option plans, which were the Mimecast Limited 2007 Key Employee Share Option Plan (the 2007 Plan), the Mimecast Limited 2010 EMI Share Option Scheme (the 2010 Plan), and the Mimecast Limited Approved Share Option Plan (the Approved Plan) (the 2007 Plan, the 2010 Plan and the Approved Plan, collectively, the Historical Plans). Upon the closing of the IPO, the Mimecast Limited 2015 Share Option and Incentive Plan (the 2015 Plan) and the 2015 Employee Share Purchase Plan (the ESPP) became effective. Subsequent to the IPO, grants of share-based awards have been made under the 2015 Plan and no further grants under the Historical Plans are permitted. The 2015 Plan allows the compensation committee to make equity-based incentive awards to our officers, employees, non-employee directors and consultants. Initially a total of 5.5 million ordinary shares were reserved for the issuance of awards under the 2015 Plan. This number is subject to adjustment in the event of a share split, share dividend or other change in our capitalization. The 2015 Plan provides that the number of shares reserved and available for issuance under the plan will automatically increase each January 1 st Under the 2015 Plan, the share option price may not be less than the fair market value of the ordinary shares on the date of grant and the term of each share option may not exceed 10 years from the date of grant. Share options typically vest over 4 years, but vesting provisions can vary based on the discretion of the board of directors. The Company settles share option exercises under the 2015 Plan through newly issued shares. The Company’s ordinary shares underlying any awards that are forfeited, canceled, withheld upon exercise of an option, or settlement of an award to cover the exercise price or tax withholding, or otherwise terminated other than by exercise will be added back to the shares available for issuance under the 2015 Plan. Initially, a total of 1.1 million shares of the Company's ordinary shares were reserved for future issuance under the ESPP. This number is subject to change in the event of a share split, share dividend or other change in capitalization. The ESPP may be terminated or amended by the board of directors at any time. The ESPP permits eligible employees to purchase shares by authorizing payroll deductions from 1% to 10% of his or her eligible compensation during an offering period, a duration of six months. Unless an employee has previously withdrawn from the offering, his or her accumulated payroll deductions will be used to purchase shares on the last day of the offering period at a price equal to 85% of the fair market value of the shares on the first business day or last business day of the offering period, whichever is lower. Share-based compensation expense recognized under the 2015 Plan, Historical Plans and ESPP in the accompanying consolidated statements of operations was as follows: Year ended March 31, 2019 2018 2017 Cost of revenue $ 1,684 $ 1,053 $ 1,353 Research and development 6,199 2,555 1,873 Sales and marketing 7,856 4,477 4,719 General and administrative 10,215 3,649 2,349 Total share-based compensation expense $ 25,954 $ 11,734 $ 10,294 In certain situations, the board of directors has approved modifications to employee share option agreements, including acceleration of vesting or the removal of exercise restrictions for share options for which the service-based vesting has been satisfied, which resulted in additional share-based compensation expense. The total modification expense in the years ended March 31, 2019, 2018 and 2017 was $3.2 million, $0.5 million and $3.0 million, respectively. Share Options Share option activity under the 2015 Plan and Historical Plans for the year ended March 31, 2019 was as follows: Number of Awards Weighted Exercise Price (2) Weighted Remaining Contractual Term (in years) Aggregate Intrinsic (in thousands) Outstanding as of March 31, 2018 6,229,860 $ 13.78 7.40 $ 134,859 Options granted 2,491,548 $ 37.15 Options exercised (2,054,813 ) $ 10.39 Options forfeited and cancelled (457,631 ) $ 25.61 Outstanding as of March 31, 2019 6,208,964 $ 23.47 7.58 $ 148,313 Exercisable as of March 31, 2019 2,054,822 $ 11.56 5.67 $ 73,538 (1) As of March 31, 2019 and 2018, the aggregate intrinsic value was calculated based on the positive difference, if any, between the closing price of our ordinary shares on the NASDAQ Global Stock Market on March 31, 2019 and 2018 respectively, and the exercise price of the underlying options. (2) Certain of the Company’s option grants have an exercise price denominated in British pounds. The weighted-average exercise price at the end of each reporting period was translated into U.S. dollars using the exchange rate at the end of the period. The weighted-average exercise price for the options granted, exercised, forfeited and cancelled was translated into U.S. dollars using the exchange rate at the applicable date of grant, exercise, forfeiture or expiration, as appropriate. The total intrinsic value of options exercised was $66.4 million, $74.2 million and $24.8 million for the years ended March 31, 2019, 2018 and 2017, respectively. Total cash proceeds from such option exercises were $21.4 million, $15.6 million and $4.5 million for the years ended March 31, 2019, 2018 and 2017, respectively. As of March 31, 2019, there was approximately $44.6 million of unrecognized share-based compensation expense related to unvested share-based awards subject to service-based vesting conditions, which is expected to be recognized over a weighted-average period of 2.83 years. ESPP The Company’s offering periods under the ESPP commence on the first business day in July and January of each year and close on the last business day of December and June, respectively. In the years ended March 31, 2019 and 2018, the Company issued 130 thousand and 64 thousand shares, respectively, in connection with its ESPP offerings and received cash proceeds of $3.3 million and $1.4 million, respectively. In the years ended March 31, 2019 and 2018, the Company recognized $1.3 million and $0.7 million of share-based compensation expense under the ESPP, respectively. RSUs The Company grants RSUs to its non-employee directors and its employees. Non-employee directors receive an initial RSU grant upon joining the board of directors that vests over three years and an annual grant each year thereafter that vests fully on the one-year anniversary of the grant date. RSUs granted to employees generally vest in four equal annual installments. RSU activity under the 2015 Plan for the year ended March 31, 2019 was as follows: Number of Shares Weighted Average Grant Date Fair Value Intrinsic Value (in thousands) (1) (2) Unvested RSUs as of March 31, 2018 32,763 $ 23.06 $ 1,161 RSUs granted 571,570 $ 37.33 21,334 RSUs vested (23,867 ) $ 23.40 919 RSUs forfeited (30,613 ) $ 36.14 1,225 Unvested RSUs as of March 31, 2019 549,853 $ 37.15 $ 26,036 (1) As of March 31, 2019 and 2018, the intrinsic value of unvested shares was calculated based on the closing price of the Company’s ordinary shares on the NASDAQ Global Select Market on March 31, 2019 and 2018, respectively, multiplied by the number of unvested RSUs. (2) The intrinsic value of RSUs granted, vested and forfeited is calculated based on the closing price of the Company’s ordinary shares at the respective transaction dates multiplied by the number of RSUs. As of March 31, 2019, there was approximately $16.5 million of unrecognized share-based compensation expense related to unvested RSUs, which is expected to be recognized over a weighted-average period of 3.14 years.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. Commitments and Contingencies The Company leases its facilities under non-cancelable operating leases and build-to-suit leases with various expiration dates through March 2029. Rent expense related to the Company’s office facilities was $5.3 million, $4.8 million and $3.2 million for the years ended March 31, 2019, 2018 and 2017, respectively. The Company has also entered into various capital lease agreements for computer equipment with non-cancelable terms through January 2022 and has non-cancelable commitments related to its data centers. Future minimum payments for our capital leases, facility operating leases (including Lexington MA – U.S. build-to-suit lease) and data center operating leases as of March 31, 2019 are as follows: Year Ending March 31, Capital Leases Facility Leases Data Centers 2020 $ 918 $ 10,649 $ 21,216 2021 1,102 15,186 17,427 2022 326 14,111 13,010 2023 — 13,825 2,774 2024 — 13,686 356 Thereafter — 59,502 — Total minimum lease payments $ 2,346 $ 126,959 $ 54,783 Less: Amount representing interest (121 ) Present value of capital lease obligations 2,225 Less: Current portion (844 ) Long-term portion of capital lease obligations $ 1,381 Certain amounts included in the table above relating to data center operating leases for the Company’s servers include usage-based charges in addition to base rent. Future lease payments in the table above do not include amounts due to the Company for future minimum sublease rental income of $0.6 million under non-cancelable subleases through 2020. The Company has outstanding letters of credit of $3.9 million and $3.8 million related to certain operating leases as of March 31, 2019 and 2018, respectively. Construction financing lease obligations The Company leases certain facilities under build-to-suit leases whereby the Company is deemed to be the owner of the building during the construction period for accounting purposes. For build-to-suit leases, during the construction period and until construction is completed, the Company records certain estimated construction costs incurred and reported to it by the landlord for the buildings as an asset within “Property and equipment, net” and a corresponding “Construction financing lease obligation” on the consolidated balance sheets because the Company is deemed to be the owner of the building during the construction period for accounting purposes Lexington, MA - U.S. Headquarters In February 2017, the Company entered into a lease agreement for a new U.S. headquarters located in a building (the Building) under construction at 191 Spring Street, Lexington, Massachusetts (191 Spring Lease). Under the terms of the 191 Spring Lease, the Company will initially lease approximately 79,145 square feet of office space for 10 years after initial occupancy commencing in January 2018. The Company executed a $1.3 million letter of credit upon signing the 191 Spring Lease. Pursuant to the work agreement entered into in connection with the 191 Spring Lease, the landlord is responsible for all costs associated with Base Building Work as defined under the 191 Spring Lease and will provide an allowance for normal tenant improvements up to an aggregate of $5.5 million. The Company has the option to extend the 191 Spring Lease for two successive five-year terms. The Company determined that it would account for the 191 Spring Lease as a build-to-suit lease as of March 31, 2017. In the year ended March 31, 2018, the construction of the Company’s Lexington, MA – U.S. headquarters was substantially completed. The Company concluded that it did not meet the sale-leaseback criteria for derecognition of the building asset and liability due to a collateralized letter of credit of $1.3 million. As a result, the Company continues to be the deemed owner of the building for accounting purposes and accounts for the lease as a financing obligation and depreciates the asset in accordance with the Company’s accounting policy. The monthly rent payments made to the lessor under the lease agreement are recorded in the Company’s financial statements as principal and interest on the financing obligation. For the years ended March 31, 2019 and 2018, interest expense on lease financing obligations was $1.9 million and $0.5 million, respectively. As of March 31, 2019, the future estimated commitments related to the financing obligations were $36.5 million and $10.0 million for principal and interest, respectively, through January 31, 2028. London, U.K. – U.K. Headquarters In January 2018, the Company entered into an Agreement for Lease (AFL) for its new U.K. headquarters located in London, England (U.K. Building). The AFL was entered into around the time the landlord had commenced a construction project to refurbish the U.K. Building and includes terms and conditions that are in effect during the construction project. The Company determined that it will account for the AFL as a build-to-suit lease as of March 31, 2018. In March 2019, the construction of the U.K. Building was substantially completed and the Company completed lease agreements (U.K. Leases) for its leased portion of the facility. Upon substantial completion of construction and execution of the U.K. Leases, the Company determined that the U.K. Leases met the criteria for “sale-leaseback” treatment and the Company derecognized the build-to-suit asset and related liability from its consolidated balance sheet as of March 31, 2019 in the amount of $56.8 million. Upon derecognition, the Company classified the U.K. L as operating leases. Future commitments related to the lease agreements are included in the table above under the caption Operating Leases. Under the U.K. Leases, the Company will initially lease approximately 113,000 square feet of space for 56.50 British pounds per square foot per year over an initial term of 15 years through March 2029 with an option to opt-out after 10 years. In the event the Company does not elect its option to opt-out, the Company has the option to extend the U.K. Leases for two successive five-year terms . Litigation The Company has been engaged in discussions over the last several months with a non-practicing patent entity regarding the entity’s patented technology and allegations regarding the Company’s past infringement of that technology, the Company’s technology and a potential commercial licensing arrangement between the parties. While no legal proceedings have been initiated, the Company has accrued $1.0 million to general and administrative expense in the fourth quarter of the fiscal year ended March 31, 2019 based on its most recent discussions with the entity. Since no legal proceedings have been initiated and the parties are in the initial stages of discussion, the Company has determined that a range of possible losses cannot be reasonably estimated. The Company anticipates that it will continue to engage in discussions with the entity regarding a commercial licensing arrangement, but there can be no assurance that the parties will enter into such an arrangement. If no agreement is reached, the entity may determine to commence legal proceedings against the Company, which could adversely impact the Company’s results of operations. If legal proceedings are commenced against the Company, the Company intends to vigorously defend itself. From time to time, the Company may be involved in legal proceedings and subject to claims in the ordinary course of business. Although the results of these proceedings and claims cannot be predicted with certainty, except as described above, the Company does not believe the ultimate cost to resolve these matters would individually, or taken together, have a material adverse effect on the Company’s business, operating results, cash flows or financial condition. Regardless of the outcome, such proceedings can have an adverse impact on the Company because of defense and settlement costs, diversion of resources and other factors, and there can be no assurances that favorable outcomes will be obtained. The Company was not subject to any material legal proceedings during the years ended March 31, 2019, 2018 and 2017, and, to the best of its knowledge, except as described above, no material legal proceedings are currently pending or threatened. Indemnification The Company typically enters into indemnification agreements with customers in the ordinary course of business. Pursuant to these agreements, the Company indemnifies and agrees to reimburse the indemnified party for losses suffered or incurred as a result of claims of intellectual property infringement. These indemnification agreements are provisions of the applicable customer agreement. Based on when clients first sign an agreement for the Company’s service, the maximum potential amount of future payments the Company could be required to make under certain of these indemnification agreements is unlimited. Based on historical experience and information known as of March 31, 2019, the Company has not incurred any costs for the above guarantees and indemnities. In certain circumstances, the Company warrants that its services will perform in all material respects in accordance with its standard published specification documentation in effect at the time of delivery of the services to the customer for the term of the agreement. To date, the Company has not incurred significant expense under its warranties and, as a result, the Company believes the estimated fair value of these agreements is immaterial.

Employee benefit plans

Employee benefit plans	12 Months Ended
	Mar. 31, 2019
Postemployment Benefits [Abstract]
Employee Benefit Plans	13. Employee Benefit Plans The Company maintains a defined contribution savings plan under Section 401(k) of the U.S. Internal Revenue Code (the 401(k) Plan), covering all U.S. employees who satisfy certain eligibility requirements. The 401(k) Plan allows each participant to defer a percentage of their eligible compensation subject to applicable annual limits pursuant to the limits established by the Internal Revenue Service. The Company’s matching contributions were $1.2 million for the year ended March 31, 2019. The Company made no matching contributions for the year ended March 31, 2018. In addition, the Company contributes to a defined contribution savings plan for its employees in the United Kingdom who satisfy certain eligibility requirements. The plan allows each participant to defer a percentage of their compensation, and the Company contributes an additional 3.0% of all wages for those employees in the scheme on a monthly basis. The Company’s contributions were $1.5 million and $0.5 million for the years ended March 31, 2019 and 2018, respectively.

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Segment and Geographic Information	14. Segment and Geographic Information Disclosure requirements about segments of an enterprise and related information establishes standards for reporting information regarding operating segments in annual financial statements and requires selected information of those segments to be presented in interim financial reports issued to shareholders. Operating segments are defined as components of an enterprise about which separate discrete financial information is available that is evaluated regularly by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is the chief executive officer. The Company and the chief executive officer view the Company’s operations and manage its business as one operating segment. Geographic Data The Company allocates, for the purpose of geographic data reporting, its revenue based upon the location of the contracting subsidiary. Total revenue by geographic area was as follows: Year ended March 31, 2019 2018 2017 United States $ 169,286 $ 128,503 $ 90,932 United Kingdom 103,900 81,720 61,188 South Africa 46,275 39,425 27,890 Other 20,916 12,249 6,553 Total revenue $ 340,377 $ 261,897 $ 186,563 Property and equipment, net by geographic location consists of the following: As of March 31, 2019 2018 United States (1) $ 62,455 $ 62,064 United Kingdom (2) 17,402 46,664 South Africa 6,170 6,512 Australia 3,481 3,953 Other 4,694 4,629 Total $ 94,202 $ 123,822 (1) Includes amounts capitalized related to the Company’s U.S. build-to-suit facility of $41.8 million and $39.4 million as of March 31, 2019 and 2018, respectively. (2) Includes amounts capitalized related to the Company’s U.K. build-to-suit facility of $31.2 million as of March 31, 2018. In March 2019, the Company derecognized the U.K. build-to-suit facility upon See Note 12 for further details

Income Taxes

Income Taxes	12 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	15. Income Taxes Loss before income taxes consists of the following: Year ended March 31, 2019 2018 2017 United Kingdom $ (4,626 ) $ (15,939 ) $ (8,162 ) Foreign (374 ) 6,258 4,923 Loss before income taxes $ (5,000 ) $ (9,681 ) $ (3,239 ) The provision for income taxes in the accompanying consolidated financial statements is comprised of the following: As of March 31, 2019 2018 2017 Current tax expense: Domestic $ — $ — $ — Foreign 3,493 2,597 2,202 Total current tax expense 3,493 2,597 2,202 Deferred tax expense: Domestic (578 ) — — Foreign (914 ) 108 — Total deferred tax expense (1,492 ) 108 — Total provision for income taxes $ 2,001 $ 2,705 $ 2,202 The reconciliation of the United Kingdom statutory tax rate to the Company’s effective tax rate included in the accompanying consolidated statements of operations is as follows: Year ended March 31, 2019 2018 2017 Tax at statutory rate 19.0 % 19.0 % 20.0 % U.S. state taxes, net of federal 31.1 14.1 (1.0 ) Foreign rate differential 26.3 36.8 (39.3 ) Meals and entertainment (11.4 ) (3.1 ) (7.4 ) Branch income / loss (0.6 ) 0.4 0.9 Share-based compensation 172.3 105.3 (4.0 ) Foreign exchange — — (24.8 ) Non-deductible interest expense — — (3.3 ) Tax credits 7.7 8.1 15.6 Unremitted earnings (3.8 ) (1.2 ) — Change in valuation allowance (249.9 ) (110.7 ) 124.7 Deferred tax true-ups (3.5 ) 8.4 (12.4 ) Tax reserves (4.9 ) (21.5 ) (117.7 ) Provision to return (0.1 ) 0.4 (0.7 ) Withholding taxes (2.6 ) (3.5 ) — Other foreign taxes — — (6.7 ) Non-deductible expenses (5.2 ) (2.4 ) (10.6 ) Deferred tax rate change (6.3 ) (77.8 ) (1.3 ) Acquisition related costs (7.6 ) — — Other (0.5 ) (0.2 ) — Effective Tax Rate (40.0 )% (27.9 )% (68.0 )% Although the Company’s parent entity is organized under Jersey law, our affairs are, and are intended to be, managed and controlled ongoing in the United Kingdom. Therefore, the Company is resident in the United Kingdom for tax purposes. The Company’s parent entity is domiciled in the United Kingdom and its earnings are subject to 19%, 19% and 20% statutory tax rate for the years ended March 31, 2019, 2018 and 2017, respectively. The Company’s effective tax rate differs from the statutory rate each year primarily due to windfall tax benefits on equity award exercises, the valuation allowance maintained against the Company’s net deferred tax assets, the jurisdictional earnings mix, tax credits, withholding taxes, and other permanent differences primarily related to non-deductible expenses. Deferred tax assets and liabilities reflect the net tax effects of net operating loss carryovers and the temporary differences between the assets and liabilities carrying value for financial reporting and the amounts used for income tax purposes. T As of March 31, 2019 2018 Deferred tax assets: Net operating loss carryforwards $ 35,120 $ 24,159 Share-based compensation 5,687 2,760 Deferred revenue 1,761 2,237 Fixed assets 4,187 3,593 Lease liability 11,748 17,024 Accrued compensation 1,211 742 Accrued costs 401 1,362 Deferred rent 320 473 Income tax credits 1,833 1,151 Other 1,247 109 Gross deferred tax assets 63,515 53,610 Deferred tax liabilities: Prepaid expenses (219 ) (315 ) Fixed assets (13,855 ) (19,280 ) Unremitted earnings (320 ) (115 ) Intangible assets (4,818 ) — Capitalized commissions (7,606 ) — Other (387 ) — Gross deferred tax liabilities (27,205 ) (19,710 ) Valuation allowance (38,318 ) (34,008 ) Deferred tax (liabilities) assets, net $ (2,008 ) $ (108 ) In assessing the ability to realize the Company’s net deferred tax assets, management considers various factors including taxable income in carryback years, future reversals of existing taxable temporary differences, tax planning strategies, and future taxable income projections to determine whether it is more likely than not that some portion or all of the net deferred tax assets will not be realized. Based on the negative evidence, including the worldwide cumulative losses that the Company has incurred, the Company has determined that the uncertainty regarding realizing its deferred tax assets is sufficient to warrant the need for a full valuation allowance against its worldwide net deferred tax assets. The $4.3 million net increase in the valuation allowance from 2018 to 2019 is primarily due to operating losses incurred and windfall tax benefits on equity awards in the current year, partially offset by the reduction in valuation allowance as a result of recording a net deferred tax liability associated with the adoption of ASC 606. In addition, the Company recognized a tax benefit of $1.0 million for the release of a portion of the Company’s pre-existing U.S. and U.K. valuation allowances as a result of the Ataata and Simply Migrate business combinations. During the third quarter of fiscal 2018, the Tax Cuts and Jobs Act (the Act) was enacted in the United States. In addition, the Securities and Exchange Commission issued guidance under Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118) that directed taxpayers to consider the impact of the U.S. legislation as “provisional” when it did not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete its accounting for the change in tax law. During 2019, the Company has completed its accounting for the tax effects of the enactment of the Act. During the year ended March 31, 2019, the Company recognized an immaterial adjustment to the provisional estimate recorded related to the Act in the Company’s fiscal 2018 financial statements. As of March 31, 2019, the Company had U.K. net operating loss carryforwards of approximately $57.4 million that do not expire. As of March 31, 2019, the Company had U.S. federal net operating loss carryforwards of approximately $78.6 million. U.S. federal net operating loss carryforwards generated through March 31, 2017 of approximately $32.5 million expire at various dates through 2037, and U.S. federal net operating loss carryforwards generated in the tax years beginning after March 31, 2017 of approximately As of March 31, 2019, the Company had Israeli net operating loss carryforwards of approximately $3.3 million that do not expire. As of March 31, 2019, the Company had Israeli income tax credit carryforwards of $0.6 million that expires in 2023 and 2024 Under Section 382 of the U.S. Internal Revenue Code, if a corporation undergoes an ownership change, the corporation’s ability to use its pre-change net operating loss carryforwards to offset its post-change income and taxes may be limited. In general, an ownership change occurs if there is a 50 percent cumulative change in ownership of the Company over a rolling three-year period. Similar rules may apply under U.S. state tax laws. The Company believes that it has experienced an ownership change in the past and may experience ownership changes in the future resulting from future transactions in our share capital, some of which may be outside the Company’s control. The Company’s ability to utilize its net operating loss carryforwards or other tax attributes to offset U.S. federal and state taxable income in the future may be subject to future limitations. As of March 31, 2019 and 2018, the Company had liabilities for uncertain tax positions of $6.0 million and $6.2 million, respectively, none of which, if recognized, would impact the Company’s effective tax rate. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: Year ended March 31, 2019 2018 Beginning balance $ 6,164 $ 4,931 Additions based on tax positions related to current year 164 142 Additions for tax positions of prior years 231 1,444 Reductions due to change in foreign exchange rate (301 ) (353 ) Expiration of statutes of limitation (165 ) — Reductions due to settlements with tax authorities (77 ) — Ending balance $ 6,016 $ 6,164 Interest and penalty charges, if any, related to uncertain tax positions are classified as income tax expense in the accompanying consolidated statements of operations. As of March 31, 2019 and 2018, the Company had immaterial accrued interest or penalties related to uncertain tax positions. The Company is subject to taxation in the United Kingdom and several foreign jurisdictions. As of March 31, 2019, the Company is no longer subject to examination by taxing authorities in the United Kingdom for years prior to March 31, 2017. The significant foreign jurisdictions in which the Company operates are no longer subject to examination by taxing authorities for years prior to March 31, 2016. In addition, net operating loss carryforwards in certain jurisdictions may be subject to adjustments by taxing authorities in future years when they are utilized. The Company had approximately $24.9 million of unremitted foreign earnings as of March 31, 2019. Income taxes have been provided on approximately $10.0 million of the unremitted foreign earnings. Income taxes have not been provided on approximately $14.9 million of unremitted foreign earnings because they are considered to be indefinitely reinvested. The tax payable on the earnings that are indefinitely reinvested would be immaterial.

Subsequent Events

Subsequent Events	12 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	16. Subsequent Events S hare Option and RSU Grants On April 1, 2019, the Company granted approximately 1.1 million share options and 0.6 million RSUs to its employees as part of its annual share-based award grant. The grant date fair value per share for share options and RSUs was $21.13 and $47.23, respectively.

Quarterly results of operations

Quarterly results of operations data (unaudited)	12 Months Ended
	Mar. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly results of operations data (unaudited)	17. Quarterly results of operations data (unaudited) The following tables set forth our unaudited quarterly consolidated statements of operations for each of the eight quarters in the period ended March 31, 2019. We have prepared the quarterly consolidated statements of operations data on a basis consistent with the audited consolidated financial statements included elsewhere in this Annual Report on Form 10-K. In the opinion of management, the financial information reflects all adjustments, consisting only of normal recurring adjustments, which we consider necessary for a fair presentation of this data. This information should be read in conjunction with the audited consolidated financial statements and related notes included elsewhere in this Annual Report on Form 10-K. The results of historical periods are not necessarily indicative of the results to be expected for any future period. Quarter ended Mar 31, Dec 31, Sep 30, Jun 30, Mar 31, Dec 31, Sep 30, Jun 30, 2019 2018 2018 2018 2018 2017 2017 2017 (in thousands, except per share amounts) Revenue $ 92,193 $ 87,611 $ 82,169 $ 78,404 $ 73,401 $ 67,272 $ 63,066 $ 58,158 Gross profit 67,491 64,353 60,231 57,428 53,225 49,544 46,523 42,906 Income (loss) from operations 207 1,572 (909 ) (2,089 ) (4,206 ) (1,129 ) (508 ) (1,111 ) Net (loss) income (1,930 ) 458 (2,058 ) (3,471 ) (6,554 ) (2,593 ) (1,339 ) (1,900 ) Net (loss) income per ordinary share: Basic $ (0.03 ) $ 0.01 $ (0.03 ) $ (0.06 ) $ (0.11 ) $ (0.05 ) $ (0.02 ) $ (0.03 ) Diluted $ (0.03 ) $ 0.01 $ (0.03 ) $ (0.06 ) $ (0.11 ) $ (0.05 ) $ (0.02 ) $ (0.03 ) Weighted-average number of ordinary shares outstanding: Basic 60,733 60,141 59,800 59,175 58,264 57,505 57,027 56,292 Diluted 60,733 62,537 59,800 59,175 58,264 57,505 57,027 56,292

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB). The Company reclassified certain amounts within its consolidated statements of cash flows to conform to current period presentation. The reclassifications include $0.2 million of loss on disposal of fixed assets to other non-cash items and $0.1 million of provision for doubtful accounts to accounts receivable for the year ended March 31, 2018. Additionally, the Company reclassified $5.6 million of unpaid purchases of capitalized software licenses to unpaid purchases of property, equipment and capitalized software within the supplemental disclosure of non-cash investing and financing activities for the year ended March 31, 2018. These reclassifications had no impact on the Company’s previously reported results of operations or its balance sheets.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the 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 estimates relied upon in preparing these consolidated financial statements include revenue recognition, variable consideration, valuation at fair value of assets acquired or sold, including intangibles, goodwill, tangible assets, and liabilities assumed, amortization periods, expected future cash flows used to evaluate the recoverability of long-lived assets, contingent liabilities, construction financing lease obligations, restructuring liabilities, expensing and capitalization of research and development costs for internal-use software, the determination of the fair value of share-based awards issued, the average period of benefit associated with costs capitalized to obtain revenue contracts and the recoverability of the Company’s net deferred tax assets and related valuation allowance. Although the Company regularly assesses these estimates, actual results could differ materially from these estimates. The Company bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances. Actual results may differ from management’s estimates if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. Changes in estimates are recorded in the period in which they become known.
Subsequent Events Considerations	Subsequent Events Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required. See Note 16.
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments The Company considers all highly liquid instruments purchased with an original maturity date of 90 days or less from the date of purchase to be cash equivalents. Cash and cash equivalents consist of cash on deposit with banks, amounts held in interest-bearing money market funds and investments with maturities of 90 days or less from the date of purchase. Cash equivalents are carried at cost, which approximates their fair market value. Investments not classified as cash equivalents are presented as either short-term or long-term investments based on both their stated maturities as well as the time period the Company intends to hold such securities. The Company determines the appropriate classification of investments at the time of purchase and reevaluates such designation at each balance sheet date. The Company adjusts the cost of investments for amortization of premiums and accretion of discounts to maturity. The Company includes such amortization and accretion in interest income. The Company has classified all of its investments as of March 31, 2019 as available-for-sale pursuant to ASC 320, Investments – Debt Securities The Company reviews investments for other-than-temporary impairment whenever the fair value of an investment is less than the amortized cost and evidence indicates that an investment’s carrying amount is not recoverable within a reasonable period of time. Other-than-temporary impairments of investments are recognized in the consolidated statements of operations if the Company has experienced a credit loss, has the intent to sell the investment, or if it is more likely than not that the Company will be required to sell the investment before recovery of the amortized cost basis. Evidence considered in this assessment includes reasons for the impairment, compliance with the Company’s investment policy, the severity and the duration of the impairment and changes in value subsequent to the end of the period. The aggregate fair value of investments held by the Company in an unrealized loss position for less than twelve months as of March 31, 2019 was $10.0 million. As of March 31, 2019, the Company determined that no other-than-temporary impairments were required to be recognized in the consolidated statements of operations. The following is a summary of cash, cash equivalents and investments as of March 31, 2019 and March 31, 2018: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2019: Cash and cash equivalents due in 90 days or less $ 137,576 $ — $ — $ 137,576 Investments: U.S. treasury securities due in one year or less 1,993 1 — 1,994 Non-U.S. government securities due in one year or less 7,969 12 — 7,981 Corporate securities due in one year or less 25,951 24 (9 ) 25,966 Total investments 35,913 37 (9 ) 35,941 Total cash, cash equivalents and investments $ 173,489 $ 37 $ (9 ) $ 173,517 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2018: Cash and cash equivalents due in 90 days or less $ 78,339 $ — $ — $ 78,339 Investments: U.S. treasury securities due in one year or less 2,995 — (5 ) 2,990 Non-U.S. government securities due in one year or less 5,996 1 (1 ) 5,996 Corporate securities due in one year or less 49,969 8 (92 ) 49,885 Total investments 58,960 9 (98 ) 58,871 Total cash, cash equivalents and investments $ 137,299 $ 9 $ (98 ) $ 137,210
Revenue Recognition	Revenue Recognition Adoption of ASC 606 Effective April 1, 2018, the Company adopted the requirements of ASU No. 2014-09, under the modified retrospective method of transition, which was applied to all customer contracts that were not completed on the effective date of ASC 606. The Company implemented internal controls and key system functionality to enable the preparation of financial information on adoption. The adoption of ASC 606 resulted in changes to the Company’s accounting policies for revenue recognition and related costs previously recognized under ASC 605, Revenue Recognition Revenue Recognition Policy Under ASC 606 the Company recognizes revenue upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. To achieve the core principle of ASC 606, the Company performs the following steps: 1) Identify the contract(s) with a customer; 2) Identify the performance obligations in the contract; 3) Determine the transaction price; 4) Allocate the transaction price to the performance obligations in the contract; and 5) Recognize revenue when (or as) the Company satisfies a performance obligation. The Company derives its revenue from two sources: (1) subscription revenues, which are comprised of subscription fees from customers accessing the Company’s cloud services and from customers purchasing additional support beyond the standard support that is included in the basic subscription fees; and (2) related professional services and other revenue, which consists primarily of certain performance obligations related to set-up, ingestion, consulting and training fees. In the years ended March 31, 2019, 2018 and 2017, subscription revenue made up the substantial majority of the Company’s revenue and professional services and other revenue made up less than 5% of the Company’s revenue. The Company’s subscription arrangements provide customers the right to access the Company’s hosted software applications. Customers do not have the right to take possession of the Company’s software during the hosting arrangement. The Company sells its products and services directly through the Company’s sales force and also indirectly through third-party resellers. In accordance with the provisions of ASC 606, the Company has considered certain factors in determining whether the end-user or the third-party reseller is the customer in arrangements involving resellers. The Company concluded that in the majority of transactions with resellers, the reseller is the customer. In these arrangements, the Company considered that it is the reseller, and not the Company, that has the relationship with the end-user. Specifically, the reseller has the ability to set pricing with the end-user and the credit risk with the end-user is borne by the reseller. Further, the reseller is not obligated to report its transaction price with the end-user to the Company, and in the majority of transactions, the Company is unable to determine the amount paid by the end-user customer to the reseller in these transactions. As a result of such considerations, revenue for these transactions is presented in the accompanying consolidated statements of operations based upon the amount billed to the reseller. For transactions where the Company has determined that the end-user is the ultimate customer, revenue is presented in the accompanying consolidated statements of operations based on the transaction price with the end-user. The Company recognizes subscription and support revenue ratably over the term of the contract, typically one year in duration, beginning on the date the customer is provided access to the Company’s service. For performance obligations related to set-up and ingestion, including implementation assistance and data migration services, respectively, the Company recognizes revenue using output measures of performance that reflect the transfer of promised services to the customer consistent with progress to completion. The Company considers training, consulting, and other professional services contracts as separate performance obligations and recognizes revenue using output measures of performance as services are completed. Amounts that have been invoiced are recorded in accounts receivable and in deferred revenue or revenue, depending on whether the revenue recognition criteria have been met. The Company primarily bills and collects payments from customers for its services in advance on a monthly and annual basis. In some instances, the Company receives non-refundable upfront payments for activities that do not constitute a promise to transfer a service and therefore are considered administrative tasks, not separate performance obligations. The upfront payments are evaluated to determine whether a material right to a discount upon renewal of the subscription exists. When the Company concludes a material right does not exist, the Company recognizes revenue related to the upfront payment over the initial contract term. When the Company concludes a material right does exist, the Company recognizes revenue related to the upfront payment, under the look-through method, over the estimated customer benefit period, which has been determined to be six years. All of the Company’s performance obligations, and associated revenue, are generally transferred to customers over time, with the exception of training, consulting and other professional services, which are generally transferred to the customer at a point in time. Revenue is presented net of any taxes collected from customers. Some of the Company’s contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative standalone selling price basis. The Company determines the standalone selling prices based on the Company’s overall pricing objectives, taking into consideration market conditions and other factors, including the value of the Company’s contracts, the products sold, customer demographics, the Company’s sales channel, and the number and size of users within the Company’s contracts. Deferred revenue primarily consists of billings or payments received in advance of revenue recognition from subscription and other services described above and is recognized as the revenue recognition criteria are met. Deferred revenue that is expected to be recognized during the succeeding twelve-month period is recorded as current deferred revenue and the remaining portion is recorded as non-current in the accompanying consolidated balance sheets. Deferred Cost Policy As part of the Company’s adoption of ASC 606 , the Company capitalizes incremental costs of obtaining revenue contracts, which primarily consist of commissions paid to its sales representatives. The Company amortizes these commissions over six years on a systematic basis, consistent with the pattern of transfer of the goods or services to which the asset relates. Six years represents the estimated benefit period of the customer relationship taking into account factors such as peer estimates of technology lives and customer lives as well as the Company's own historical data. No commissions are paid related to contract renewals. The current and noncurrent portions of deferred commissions are included in deferred contract costs, net, and deferred contract costs, net of current portion, respectively, in the accompanying consolidated balance sheets. Impact of Adoption of ASC 606 The adoption of ASC 606 resulted in a decrease to deferred revenue of $6.0 million and an increase of $23.8 million in deferred contract costs as of April 1, 2018. The Company recorded the deferred tax impact associated with the cumulative effect adjustment of adopting ASC 606 to accumulated deficit with an equal and offsetting adjustment to the Company’s valuation allowance. The decrease to deferred revenue upon adoption was primarily due to a change in the accounting treatment for certain upfront fees that were accounted for as a single unit of account under Legacy GAAP and are accounted for as separate performance obligations under ASC 606. The increase in deferred contract costs was the result of the capitalization of certain commissions that were determined to be incremental costs of obtaining a contract. Under Legacy GAAP, the Company expensed all commission costs as incurred. As a result of the adoption of ASC 606, the Company’s accumulated deficit decreased by $29.9 million as of April 1, 2018, which was the net cumulative impact associated with the capitalization of sales commissions and the adjustment to deferred revenue. The cumulative effect of the changes made to the Company’s April 1, 2018 balance sheet for the adoption of ASC 606 was as follows: Balance as of March 31, 2018 Adjustments Due to Adoption of ASC 606 Balance as of April 1, 2018 Assets Deferred contract costs, net $ — $ 5,494 $ 5,494 Deferred contract costs, net of current portion — 18,339 18,339 Liabilities Deferred revenue 123,057 (517 ) 122,540 Deferred revenue, net of current portion 18,045 (5,526 ) 12,519 Shareholders' equity Accumulated deficit (106,507 ) 29,876 (76,631 ) In accordance with the requirements of ASC 606, the disclosure for the quantitative effect and the significant changes between the reported results under ASC 606 and those that would have been reported under Legacy GAAP on our consolidated statements of operations and balance sheet are as follows: Year ended March 31, 2019 As Reported - ASC 606 Amounts without Adoption of ASC 606 Effect of Change Increase/(Decrease) Income Statement Revenues $ 340,377 $ 338,829 $ 1,548 Operating expenses Sales and marketing (139,194 ) (153,003 ) (13,809 ) Net loss $ (7,001 ) $ (22,358 ) $ 15,357 As of March 31, 2019 As Reported - ASC 606 Balances without Adoption of ASC 606 Effect of Change Increase/(Decrease) Balance Sheet Assets Deferred contract costs, net $ 8,140 $ — $ 8,140 Deferred contract costs, net of current portion 28,250 — 28,250 Liabilities Deferred revenue 163,102 161,746 1,356 Deferred revenue, net of current portion 12,472 21,336 (8,864 ) Shareholders' equity Accumulated deficit (83,632 ) (128,865 ) 45,233 Revenue recognized during the twelve months ended March 31, 2019 from amounts included in deferred revenue at the beginning of the period was approximately $118.7 million. Revenue recognized during the twelve months ended March 31, 2019 from performance obligations satisfied or partially satisfied in previous periods was not material. The adoption of ASC 606 had no impact to net operating cash flows. Contracted revenue as of March 31, 2019 that has not yet been recognized (contracted and not recognized) was $86.0 million, which includes deferred revenue and non-cancellable amounts that will be invoiced and recognized as revenue in future periods and excludes contracts with an original expected length of one year or less. The Company expects 51% of contracted and not recognized revenue to be recognized over the next twelve months, 46% in years two and three, with the remaining balance recognized thereafter.
Cost of Revenue	Cost of Revenue Cost of revenue primarily consists of expenses related to supporting and hosting the Company’s product offerings and delivering professional services. These costs include salaries, benefits, incentive compensation and share-based compensation expense related to the management of the Company’s data centers, customer support team and the Company’s professional services team. In addition to these costs, the Company incurs third-party service provider costs such as data center and networking expenses, allocated overhead, amortization of capitalized software and acquired
Concentration of Credit Risk and Off-Balance Sheet Risk	Concentration of Credit Risk and Off-Balance Sheet Risk The Company has no off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments, which potentially subject us to concentrations of credit risk, consist primarily of cash and cash equivalents, investments and accounts receivable. The Company maintains its cash and cash equivalents with major financial institutions of high-credit quality. Although the Company deposits its cash with multiple financial institutions, its deposits, at times, may exceed federally insured limits. Credit risk with respect to accounts receivable is dispersed due to our large number of customers. The Company’s accounts receivable balances are derived from revenue earned from customers primarily located in the United Kingdom, the United States, and South Africa. The Company generally does not require its customers to provide collateral or other security to support accounts receivable. Credit losses historically have not been significant and the Company generally has not experienced any material losses related to receivables from individual customers, or groups of customers. Due to these factors, no additional credit risk beyond amounts provided for collection losses is believed by management to be probable in the Company’s accounts receivable. As of March 31, 2019 and 2018, no individual customer represented more than 10% of our accounts receivable. During the years ended March 31, 2019, 2018 and 2017, no individual customer represented more than 10% of our revenue. The Company's board of directors approved investment policy permits investments in fixed income securities denominated and payable in U.S. dollars including U.S. government and agency securities, non-U.S. government securities, money market instruments, commercial paper, certificates of deposit, corporate bonds and asset-backed securities. The Company diversifies its investment portfolio by investing in multiple types of investment-grade securities across various industries and issuers, limiting the amount invested in individual securities and limiting the average maturity to two years or less. As of March 31, 2019, the Company’s investments consisted primarily of investment-grade fixed income corporate debt securities with maturities ranging from 1 to 7 months, non-U.S. government securities with maturities ranging from 3 to 8 months and U.S. treasury securities with maturities in approximately 5 months.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The Company makes judgments as to its ability to collect outstanding receivables and provide allowances for the portion of receivables when a loss is reasonably expected to occur. The allowance for doubtful accounts is established to represent the best estimate of the net realizable value of the outstanding accounts receivable. The development of the allowance for doubtful accounts is based on a review of past due amounts, historical write-off and recovery experience, as well as aging trends affecting specific accounts and general operational factors affecting all amounts. In addition, factors are developed utilizing historical trends in bad debts, returns and allowances. The Company considers current economic trends when evaluating the adequacy of the allowance for doubtful accounts. If circumstances relating to specific customers change or unanticipated changes occur in the general business environment, the Company’s estimates of the recoverability of receivables could be further adjusted. For the years ended March 31, 2019, 2018 and 2017, bad debt expense was $0.2 million, $0.2 million and $0.1 million, respectively. The allowance for doubtful accounts as of March 31, 2019 and 2018 was not material.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, and are depreciated using the straight-line method over the estimated useful life of the assets. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the related asset. Property and equipment acquired under capital leases is amortized over the lease term or, in circumstances where ownership is transferred by the end of the lease or there is a bargain purchase option, over the useful life that would be assigned if the asset were owned. Upon retirement or sale, the cost of assets disposed of, and the related accumulated depreciation, are removed from the accounts, and any resulting gain or loss is included in the determination of net loss in the period of retirement or sale. The estimated useful lives of the Company’s property and equipment are as follows: Estimated Useful Life Buildings and building improvements (1) 10 Computer equipment 3 to 5 Leasehold improvements Lesser of asset life or lease term Furniture and fixtures 5 Office equipment 3 (1) Building and building improvement assets under build-to-suit accounting are depreciated over their useful lives during the lease period. Expenditures for maintenance and repairs are charged to expense as incurred, whereas major betterments are capitalized as additions to property and equipment.
Business Combinations	Business Combinations In accordance with ASC 805, 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 value of the assets acquired and the liabilities assumed and represents the expected future economic benefits arising from other assets acquired that are not individually identified and separately recognized. While the Company uses its best estimates and assumptions as 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. Assumptions may be incomplete or inaccurate, and unanticipated events or circumstances may occur, which may affect the accuracy or validity of such assumptions, estimates or actual results. 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 it 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 consolidated statements of operations.
Goodwill and acquired intangible assets	Goodwill and acquired intangible assets Goodwill is not amortized, but is evaluated for impairment annually, or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The Company has determined that there is a single reporting unit for the purpose of conducting this goodwill impairment assessment. For purposes of assessing potential impairment, the Company estimates the fair value of the reporting unit, based on the Company’s market capitalization, and compares this amount to the carrying value of the reporting unit. If the Company determines that the carrying value of the reporting unit exceeds its fair value, an impairment charge would be required. The annual goodwill impairment test is performed as of January 1 st Intangible assets acquired in a business combination are recorded at their estimated fair values at the date of acquisition. The Company amortizes acquired definite-lived intangible assets over their estimated useful lives based on the pattern of consumption of the economic benefits or, if that pattern cannot be readily determined, on a straight-line basis.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets, including property and equipment and definite-lived intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. During this review, the Company re-evaluates the significant assumptions used in determining the original cost and estimated lives of long-lived assets. Although the assumptions may vary from asset to asset, they generally include operating results, changes in the use of the asset, cash flows, and other indicators of value. Management then determines whether the remaining useful life continues to be appropriate, or whether there has been an impairment of long-lived assets based primarily upon whether expected future undiscounted cash flows are sufficient to support the recoverability of these assets. Recoverability of these assets is measured by comparison of the carrying amount of the asset to the future undiscounted cash flows the asset is expected to generate. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. For the years ended March 31, 2019 and 2017, the Company did not identify any impairment of its long-lived assets. For the year ended March 31, 2018, the Company recorded an i
Fair Value Measurements	Fair Value Measurements ASC 820, Fair Value Measurements and Disclosures, ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants based on the highest and best use of the asset or liability. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. The Company uses valuation techniques to measure fair value that maximize the use of observable inputs and minimize the use of unobservable inputs. These inputs are prioritized as follows: • Level 1 inputs—Unadjusted observable quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2 inputs—Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. • Level 3 inputs—Unobservable inputs for determining the fair values of assets or liabilities that reflect an entity’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company evaluates assets and liabilities subject to fair value measurements on a recurring and nonrecurring basis to determine the appropriate level to classify them for each reporting period. The Company measures eligible assets and liabilities at fair value, with changes in value recognized in earnings. Fair value treatment may be elected either upon initial recognition of an eligible asset or liability or, for an existing asset or liability, if an event triggers a new basis of accounting. The Company did not elect to remeasure any of its existing financial assets or liabilities, and did not elect the fair value option for any financial assets and liabilities transacted in the years ended March 31, 2019, 2018 and 2017.
Internal-use Software Costs	Software Development Costs Costs incurred to develop software applications used in the Company’s SaaS platform consist of certain direct costs of materials and services incurred in developing or obtaining internal-use computer software, and payroll and payroll-related costs for employees who are directly associated with, and who devote time to, the project. These costs generally consist of internal labor during configuration, coding, and testing activities. Research and development costs incurred during the preliminary project stage or costs incurred for data conversion activities, training, maintenance and general and administrative or overhead costs are expensed as incurred. Once an application has reached the development stage, internal and external costs, if direct and incremental, are capitalized until the application is substantially complete and ready for its intended use. Qualified costs incurred during the operating stage of the Company’s software applications relating to upgrades and enhancements are capitalized to the extent it is probable that they will result in added functionality, while costs incurred for maintenance of, and minor upgrades and enhancements to, internal-use software are expensed as incurred. During the years ended March 31, 2019, 2018 and 2017, the Company believes the substantial majority of its development efforts were either in the preliminary project stage of development or in the operation stage (post-implementation), and accordingly, no costs have been capitalized during these periods. These costs are included in the accompanying consolidated statements of operations as research and development expense. Capitalized software and Cloud-computing Arrangements (CCA) The Company accounts for acquired internal-use software licenses and certain costs related to video content production related to its awareness training offering within the scope of ASC 350-40 as intangible assets (Capitalized Software). Acquired internal-use software licenses are amortized over the term of the arrangement to the line item within the consolidated statements of operations that reflects the nature of the license. Video production costs are amortized to cost of revenue over their expected useful life of five years when the content is ready for use. See Note 6 for further details. Additionally, the Company evaluates its accounting for fees paid in a CCA to determine whether the CCA includes a license to internal-use software. If the CCA includes a software license, the Company accounts for the software license as an intangible asset. Acquired software licenses are recognized and measured at cost, which includes the present value of the license obligation if the license is to be paid for over time. If the CCA does not include a software license, the Company accounts for the arrangement as a service contract (hosting arrangement) and hosting costs are generally expensed as incurred. Upon adoption of ASU 2018-15, Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-24): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract
Foreign Currency Translation	Foreign Currency Translation The reporting currency of the Company is the U.S. dollar. The Company determines the functional currency for its non-U.S. subsidiaries by reviewing the currencies in which its respective operating activities occur. The functional currency of the Company’s non-U.S. subsidiaries is generally the local currency of each subsidiary. All assets and liabilities in the balance sheets of entities whose functional currency is a currency other than the U.S. dollar are translated into U.S. dollar equivalents at exchange rates as follows: (i) asset and liability accounts at period-end rates, (ii) income statement accounts at weighted-average exchange rates for the period, and (iii) shareholders’ equity accounts at historical exchange rates. Foreign exchange transaction gains and losses are included in foreign exchange (expense) income and other, net in the accompanying consolidated statements of operations. The effects of foreign currency translation adjustments are included as a component of accumulated other comprehensive loss in the accompanying consolidated balance sheets.
Net Loss Per Share	Net Loss Per Ordinary Share The Company calculates basic and diluted net loss per ordinary share by dividing net loss by the weighted-average number of ordinary shares outstanding during the period. The Company has excluded other potentially dilutive shares, which include outstanding options to purchase ordinary shares and unvested restricted share units (RSUs), from the weighted-average number of ordinary shares outstanding as their inclusion in the computation for all periods would be anti-dilutive due to net losses incurred. The following potentially dilutive ordinary share equivalents have been excluded from the calculation of diluted weighted-average shares outstanding for the years ended March 31, 2019, 2018 and 2017 as their effect would have been anti-dilutive for the periods presented (in thousands): Year Ended March 31, 2019 2018 2017 Share options outstanding 6,209 6,230 8,681 Unvested RSUs 550 33 28
Advertising and Promotion Costs	Advertising and Promotion Costs Expenses related to advertising and promotion of solutions is charged to sales and marketing expense as incurred. The Company incurred advertising expenses of $12.5 million, $12.4 million and $11.5 million during the years ended March 31, 2019, 2018 and 2017, respectively.
Income Taxes	Income Taxes The Company is subject to income tax in the United Kingdom, the United States and other international jurisdictions, and uses estimates in determining its provision for income taxes. The Company accounts for income taxes in accordance with ASC 740, Income Taxes The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not the tax position will be sustained on examination by the tax authorities, based on the technical merits of the position. The tax benefits recognized in the consolidated financial statements from such position are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement. As of March 31, 2019 and 2018, the Company did not have any uncertain tax positions that would impact our net tax provision if recognized.
Share-Based Compensation	Share-Based Compensation The Company accounts for share-based compensation awards in accordance with the provisions of ASC 718, Compensation—Stock Compensation See Note 11 for further description of the Company’s share-based compensation plans and a summary of the share-based award activity for the year ended March 31, 2019. Share Options The Company estimates the fair value of employee share options on the date of grant using the Black-Scholes option-pricing model, which requires the use of highly subjective estimates and assumptions. The Company estimates the expected term of share options for service-based awards utilizing the “Simplified Method,” as it does not have sufficient historical share option exercise information on which to base its estimate. The Simplified Method is based on the average of the vesting tranches and the contractual life of each grant. The risk-free interest rate is based on a treasury instrument whose term is consistent with the expected life of the share option. Since there was no public market for the Company’s ordinary shares prior to the IPO and as its shares have been publicly traded for a limited time, the Company determined the expected volatility for options granted based on an analysis of reported data for a peer group of companies that issue options with substantially similar terms. The expected volatility of options granted has been determined using an average of the historical volatility measures of this peer group of companies. The Company uses an expected dividend rate of zero as it currently has no history or expectation of paying dividends on its ordinary shares. The fair value of the Company’s ordinary shares at the time of each share option grant is based on the closing market value of its ordinary shares on the grant date. The fair value of each share option grant was estimated using the Black-Scholes option-pricing model that used the following weighted-average assumptions: Year ended March 31, 2019 2018 2017 Expected term (in years) 6.1 6.1 6.1 Risk-free interest rate 2.7 % 2.2 % 2.1 % Expected volatility 41.5 % 39.8 % 41.0 % Expected dividend yield — % — % — % Estimated grant date fair value per ordinary share $ 37.15 $ 26.52 $ 20.22 The weighted-average per share fair value of share options granted to employees during the years ended March 31, 2019, 2018 and 2017 was $16.48, $11.12 and $8.65 per share, respectively. Employee Share Purchase Plan (ESPP) The Company estimates the fair value of its ESPP share options on the date of grant using the Black-Scholes option-pricing model, which requires the use of highly subjective estimates and assumptions. The Company estimates the expected term of ESPP share options based on the length of each offering period, which is six months. The risk-free interest rate is based on a treasury instrument whose term is consistent with the expected life of the ESPP share option. Expected volatility is based on the Company’s historical volatility. The Company uses an expected dividend rate of zero as it currently has no history or expectation of paying dividends on its ordinary shares. The grant date fair value per ordinary share is based on the closing market value of its ordinary shares on the first day of each ESPP offering period. The first authorized offering period under the ESPP commenced on July 1, 2017. The fair value of each ESPP option grant was estimated using the Black-Scholes option-pricing model that used the following weighted-average assumptions: Year ended March 31, 2019 2018 Expected term (in years) 0.5 0.5 Risk-free interest rate 2.3 % 1.4 % Expected volatility 39.1 % 29.9 % Expected dividend yield — % — % Grant date fair value per ordinary share $ 36.69 $ 27.15 The weighted-average per share fair value of ESPP share options granted to employees during the years ended March 31, 2019 and 2018, was $9.58 and $6.41, respectively. RSUs For RSUs issued under the Company’s share-based compensation plans, the fair value of each grant is calculated based on the closing market value of its ordinary shares on the date of grant.
Leases	Leases The Company categorizes leases at their inception as either operating or capital leases. On certain lease agreements, the Company may receive rent holidays and other incentives. The Company recognizes lease costs on a straight-line basis once control of the space is achieved, without regard to deferred payment terms, such as rent holidays that defer the commencement date of required payments or escalating payment amounts. The difference between required lease payments and rent expense has been recorded as deferred rent. Additionally, incentives received are treated as a reduction of costs over the term of the agreement, as they are considered an inseparable part of the lease agreement. The Company generally leases office facilities and data center facilities under non-cancelable, operating lease agreements. The Company establishes assets and liabilities for the estimated construction costs incurred under certain lease arrangements where it is considered the owner for accounting purposes only, or build-to-suit leases, to the extent it is involved in the construction of structural improvements or take construction risk prior to commencement of a lease. Accordingly, the Company records the estimated fair value of the building as of the lease inception date and its portion of project construction costs incurred by the landlord as an asset in “Property and equipment, net” and a related financing obligation in “Construction financing lease obligation” on the Company’s consolidated balance sheet.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as the change in equity of a business enterprise during a period from transactions, other events, and circumstances from non-owner sources. Comprehensive loss consists of net loss and other comprehensive (loss) income, which includes certain changes in equity that are excluded from net loss. As of March 31, 2019 and 2018, accumulated other comprehensive loss is presented separately on the consolidated balance sheets and consists of cumulative foreign currency translation adjustments and unrealized gains and losses on investments.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued and Adopted Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. Recently Adopted Accounting Pronouncements On April 1, 2018, the Company adopted ASU No. 2014-09. The core principle of ASU 2014-09 is to recognize revenue when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. ASU 2014-09 defines a five-step process to achieve this core principle and, in doing so, it is possible more judgment and estimates may be required within the revenue recognition process than required under legacy GAAP, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. See Revenue Recognition section above in this Note 2 for the impact of the adoption on revenue recognition and accounting for costs to obtain a contract. On April 1, 2018 the Company adopted ASU No. 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities On April 1, 2018 the Company adopted ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments On April 1, 2018 the Company adopted ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory On April 1, 2018 the Company adopted ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash On April 1, 2018 the Company adopted ASU 2017-01, Business Combinations (Topic 805) - Clarifying the Definition of a Business On April 1, 2018 the Company adopted ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting On July 1, 2018, the Company adopted ASU 2018-15 on a prospective basis. ASU 2018-15 requires a customer in a cloud computing arrangement that is a service contract (hosting arrangement) to follow the internal use software guidance in ASC 350-40 to determine which implementation costs to capitalize as assets or expense as incurred. See Capitalized Software and Cloud Computing Arrangements section above within this Note 2 for the impact of the adoption. Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) The Company is completing its evaluation of the impact of ASU 2016-02 on its consolidated financial statements, including its assessment of build-to suit leases. The Company expects that the adoption will have a material impact on the consolidated balance sheets and related disclosures with the recognition of significant right-of-use assets and lease liabilities. The Company currently expects that the majority of its operating leases and data center leases, as disclosed in Note 12, will be subject to the new standard. The Company does not expect the adoption to have a material impact on its consolidated statements of operations or cash flows nor will the adoption have a material impact on the Company's liquidity or on the Company's compliance with its debt covenants. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment . In June 2018, the FASB issued ASU 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Mar. 31, 2019
Schedule of Cash, Cash Equivalents And Investments	The following is a summary of cash, cash equivalents and investments as of March 31, 2019 and March 31, 2018: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2019: Cash and cash equivalents due in 90 days or less $ 137,576 $ — $ — $ 137,576 Investments: U.S. treasury securities due in one year or less 1,993 1 — 1,994 Non-U.S. government securities due in one year or less 7,969 12 — 7,981 Corporate securities due in one year or less 25,951 24 (9 ) 25,966 Total investments 35,913 37 (9 ) 35,941 Total cash, cash equivalents and investments $ 173,489 $ 37 $ (9 ) $ 173,517 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value March 31, 2018: Cash and cash equivalents due in 90 days or less $ 78,339 $ — $ — $ 78,339 Investments: U.S. treasury securities due in one year or less 2,995 — (5 ) 2,990 Non-U.S. government securities due in one year or less 5,996 1 (1 ) 5,996 Corporate securities due in one year or less 49,969 8 (92 ) 49,885 Total investments 58,960 9 (98 ) 58,871 Total cash, cash equivalents and investments $ 137,299 $ 9 $ (98 ) $ 137,210
Estimated Useful Lives of Property and Equipment	The estimated useful lives of the Company’s property and equipment are as follows: Estimated Useful Life Buildings and building improvements (1) 10 Computer equipment 3 to 5 Leasehold improvements Lesser of asset life or lease term Furniture and fixtures 5 Office equipment 3 (1) Building and building improvement assets under build-to-suit accounting are depreciated over their useful lives during the lease period.
Dilutive Ordinary Shares Excluded from Calculation of Diluted Weighted Average Shares Outstanding	The following potentially dilutive ordinary share equivalents have been excluded from the calculation of diluted weighted-average shares outstanding for the years ended March 31, 2019, 2018 and 2017 as their effect would have been anti-dilutive for the periods presented (in thousands): Year Ended March 31, 2019 2018 2017 Share options outstanding 6,209 6,230 8,681 Unvested RSUs 550 33 28
Summary of Weighted Average Assumption Utilized to Determine Fair Value of Option	The fair value of each share option grant was estimated using the Black-Scholes option-pricing model that used the following weighted-average assumptions: Year ended March 31, 2019 2018 2017 Expected term (in years) 6.1 6.1 6.1 Risk-free interest rate 2.7 % 2.2 % 2.1 % Expected volatility 41.5 % 39.8 % 41.0 % Expected dividend yield — % — % — % Estimated grant date fair value per ordinary share $ 37.15 $ 26.52 $ 20.22
Summary of Assumptions Used in Black-Scholes Option Pricing Model to Estimate Fair Value of Shares Under the ESPP	The fair value of each ESPP option grant was estimated using the Black-Scholes option-pricing model that used the following weighted-average assumptions: Year ended March 31, 2019 2018 Expected term (in years) 0.5 0.5 Risk-free interest rate 2.3 % 1.4 % Expected volatility 39.1 % 29.9 % Expected dividend yield — % — % Grant date fair value per ordinary share $ 36.69 $ 27.15
ASU 2014-09 [Member]
Schedule of Cumulative Effect of Changes to Balance Sheet	The cumulative effect of the changes made to the Company’s April 1, 2018 balance sheet for the adoption of ASC 606 was as follows: Balance as of March 31, 2018 Adjustments Due to Adoption of ASC 606 Balance as of April 1, 2018 Assets Deferred contract costs, net $ — $ 5,494 $ 5,494 Deferred contract costs, net of current portion — 18,339 18,339 Liabilities Deferred revenue 123,057 (517 ) 122,540 Deferred revenue, net of current portion 18,045 (5,526 ) 12,519 Shareholders' equity Accumulated deficit (106,507 ) 29,876 (76,631 )
Schedule of Quantitative Effect and Significant Changes Between ASC 606 and Legacy GAAP on Unaudited Condensed Consolidated Income Statement and Balance Sheet	In accordance with the requirements of ASC 606, the disclosure for the quantitative effect and the significant changes between the reported results under ASC 606 and those that would have been reported under Legacy GAAP on our consolidated statements of operations and balance sheet are as follows: Year ended March 31, 2019 As Reported - ASC 606 Amounts without Adoption of ASC 606 Effect of Change Increase/(Decrease) Income Statement Revenues $ 340,377 $ 338,829 $ 1,548 Operating expenses Sales and marketing (139,194 ) (153,003 ) (13,809 ) Net loss $ (7,001 ) $ (22,358 ) $ 15,357 As of March 31, 2019 As Reported - ASC 606 Balances without Adoption of ASC 606 Effect of Change Increase/(Decrease) Balance Sheet Assets Deferred contract costs, net $ 8,140 $ — $ 8,140 Deferred contract costs, net of current portion 28,250 — 28,250 Liabilities Deferred revenue 163,102 161,746 1,356 Deferred revenue, net of current portion 12,472 21,336 (8,864 ) Shareholders' equity Accumulated deficit (83,632 ) (128,865 ) 45,233

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consists of the following: As of March 31, 2019 2018 Prepaid expenses $ 11,259 $ 10,766 Lease incentive due from landlord 8,900 — Research and development investment tax credits 3,862 3,353 Other current assets 1,850 1,183 Total prepaid expenses and other current assets $ 25,871 $ 15,302
Schedule of Property and Equipment, Net	Property and equipment, net, consists of the following: As of March 31, 2019 2018 Building and building improvements (1) $ 47,001 $ 75,165 Computer equipment (2) 112,277 102,821 Leasehold improvements 8,166 6,504 Furniture and fixtures 4,590 4,187 Office equipment 1,345 1,172 173,379 189,849 Less: Accumulated depreciation and amortization (1) (2) (79,177 ) (66,027 ) Property and equipment, net $ 94,202 $ 123,822 (1 ) As of March 31, 2019 2018 U.S. build-to-suit facility $ 47,001 $ 43,925 U.K. build-to-suit facility — 31,240 Less: Accumulated depreciation (5,164 ) (753 ) $ 41,837 $ 74,412 As of March 31, 2019 and 2018, the U.S. build-to-suit facility includes company-funded building improvements of $5.2 million and $4.5 million, respectively. In March 2019, the Company derecognized the U.K. build-to-suit facility upon substantial completion of construction (2) Includes property and equipment acquired under capital leases: As of March 31, 2019 2018 Computer equipment $ 4,754 $ 4,713 Less: Accumulated amortization (2,228 ) (990 ) $ 2,526 $ 3,723
Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consists of the following: As of March 31, 2019 2018 Accrued payroll and related benefits $ 21,198 $ 15,325 Accrued taxes payable 5,305 4,029 Construction financing lease obligation 2,670 2,421 Restructuring liability 49 851 Other accrued expenses 15,087 11,252 Total accrued expenses and other current liabilities $ 44,309 $ 33,878
Other Non-current Liabilities	Other non-current liabilities consists of the following: As of March 31, 2019 2018 Deferred rent $ 10,218 $ 840 Restructuring liability — 74 Other non-current liabilities 5,363 4,040 Total other non-current liabilities $ 15,581 $ 4,954

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Summary of Preliminary Purchase Price Allocation	The following table summarizes the preliminary purchase price allocation as of March 31, 2019 (in thousands): Preliminary purchase consideration: Total cash paid, net of acquired cash $ 85,258 Cash and cash equivalents acquired 10,410 Fair value of previously held asset 828 Total preliminary purchase price consideration $ 96,496 Fair value of assets acquired and liabilities assumed: Cash and cash equivalents $ 10,410 Prepaid expenses and other current assets 76 Intangible assets 16,964 Goodwill 74,469 Total assets acquired 101,919 Accounts payable (18 ) Accrued expenses and other current liabilities (2,345 ) Deferred revenue (663 ) Other non-current liabilities (2,397 ) Total fair value of assets acquired and liabilities assumed $ 96,496
Summary of Estimated Fair Values and Useful Lives of Identifiable Intangible	The following table presents the estimated fair values and useful lives of the identifiable intangible assets acquired: Amount (in thousands) Estimated Useful Life (in years) Developed technology $ 16,689 10 Customer relationships 235 7 Trade names 40 1 Total identifiable intangible assets $ 16,964
Summary of Pro Forma Financial Information (unaudited)	Accordingly, these unaudited pro forma results are presented for informational purposes only and are not necessarily indicative of the results of operations that would have been achieved had the acquisition occurred as of April 1, 2017, nor are they intended to represent or be indicative of future results of operations (in thousands, except per share amounts): Year ended March 31, 2019 2018 Revenue $ 340,824 $ 262,773 Net loss (7,729 ) (17,359 ) Basic net loss per share $ (0.13 ) $ (0.30 ) Diluted net loss per share $ (0.13 ) $ (0.30 ) Weighted average number of ordinary shares outstanding Basic and diluted 59,960 57,269

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Mar. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Goodwill Balance	The following table reflects goodwill activity in each of the periods presented: Year ended March 31, 2019 2018 Beginning balance $ 5,631 $ 5,363 Goodwill acquired 101,381 226 Effect of foreign exchange rates 563 42 Ending balance $ 107,575 $ 5,631
Schedule of Purchased Intangible Assets	Purchased intangible assets consist of the following: Weighted- Average March 31, 2019 Remaining Gross Net Useful Life Carrying Accumulated Carrying (in years) Value Amortization Value Developed technology 9 $ 23,577 $ (1,707 ) $ 21,870 Customer relationships 6 455 (73 ) 382 Trade names 1 56 (34 ) 22 Capitalized software (1) 3 12,431 (4,082 ) 8,349 $ 36,519 $ (5,896 ) $ 30,623 Weighted- Average March 31, 2018 Remaining Gross Net Useful Life Carrying Accumulated Carrying (in years) Value Amortization Value Developed technology 9 1,546 (213 ) 1,333 Customer relationships 6 108 (21 ) 87 Capitalized software 3 9,171 (1,329 ) 7,842 10,825 (1,563 ) 9,262 In-process research and development (2) 557 — 557 $ 11,382 $ (1,563 ) $ 9,819 (1) Includes $0.4 million of costs capitalized related to video production costs. See Note 2 for further information. (2) In-process research and development assets were placed in service in the year ended March 31, 2019.
Schedule of Future Estimated Amortization Expense of Acquired Intangible Assets	Future estimated amortization expense of intangible assets as of March 31, 2019 is as follows: Purchased Intangible Capitalized Assets Software 2020 $ 2,582 $ 3,522 2021 2,560 2,790 2022 2,560 1,420 2023 2,560 528 Thereafter 12,012 89 Total $ 22,274 $ 8,349

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	12 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured and Recorded at Fair Value on Recurring Basis	The following table summarizes financial assets measured and recorded at fair value on a recurring basis in the accompanying consolidated balance sheets as of March 31, 2019 and 2018, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: March 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs) Significant Other Observable Inputs (Level 2 Inputs) Total Assets: Money market funds $ 8,348 $ — $ 8,348 U.S. treasury securities — 1,994 1,994 Non-U.S. government securities — 7,981 7,981 Corporate securities — 25,966 25,966 Total assets $ 8,348 $ 35,941 $ 44,289 March 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs) Significant Other Observable Inputs (Level 2 Inputs) Total Assets: Money market funds $ 10,143 $ — $ 10,143 U.S. treasury securities — 2,990 2,990 Non-U.S. government securities — 5,996 5,996 Corporate securities — 49,885 49,885 Total assets $ 10,143 $ 58,871 $ 69,014

Debt (Tables)

Debt (Tables)	12 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Future Minimum Principal Payment Obligations	Future minimum principal payment obligations under the Term Loan are as follows: Year Ending March 31, Debt 2020 $ 4,375 2021 6,875 2022 9,375 2023 10,000 2024 67,500 Total minimum debt payments $ 98,125 Less: Debt issuance costs $ (1,269 ) Less: Current portion of long-term debt $ (4,059 ) Long-term debt $ 92,797

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Summary of Ordinary Share Reserved for Future Issuance under 2015 Plan, Historical Plans and ESPP	As of March 31, 2019, the following ordinary shares were reserved for future issuance under the 2015 Plan, Historical Plans and ESPP (as defined below in Note 11): As of March 31, 2019 Options outstanding under share option plans 6,208,964 Unvested RSUs 549,853 Options and awards available for future grant under the 2015 Plan 9,138,803 Shares reserved for issuance under ESPP 905,114 Total authorized ordinary shares reserved for future issuance 16,802,734

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation Expense Recognized in Statements of Operations	Share-based compensation expense recognized under the 2015 Plan, Historical Plans and ESPP in the accompanying consolidated statements of operations was as follows: Year ended March 31, 2019 2018 2017 Cost of revenue $ 1,684 $ 1,053 $ 1,353 Research and development 6,199 2,555 1,873 Sales and marketing 7,856 4,477 4,719 General and administrative 10,215 3,649 2,349 Total share-based compensation expense $ 25,954 $ 11,734 $ 10,294
Schedule of Share-Based Compensation, Stock Options, Activity	Share option activity under the 2015 Plan and Historical Plans for the year ended March 31, 2019 was as follows: Number of Awards Weighted Exercise Price (2) Weighted Remaining Contractual Term (in years) Aggregate Intrinsic (in thousands) Outstanding as of March 31, 2018 6,229,860 $ 13.78 7.40 $ 134,859 Options granted 2,491,548 $ 37.15 Options exercised (2,054,813 ) $ 10.39 Options forfeited and cancelled (457,631 ) $ 25.61 Outstanding as of March 31, 2019 6,208,964 $ 23.47 7.58 $ 148,313 Exercisable as of March 31, 2019 2,054,822 $ 11.56 5.67 $ 73,538 (1) As of March 31, 2019 and 2018, the aggregate intrinsic value was calculated based on the positive difference, if any, between the closing price of our ordinary shares on the NASDAQ Global Stock Market on March 31, 2019 and 2018 respectively, and the exercise price of the underlying options. (2) Certain of the Company’s option grants have an exercise price denominated in British pounds. The weighted-average exercise price at the end of each reporting period was translated into U.S. dollars using the exchange rate at the end of the period. The weighted-average exercise price for the options granted, exercised, forfeited and cancelled was translated into U.S. dollars using the exchange rate at the applicable date of grant, exercise, forfeiture or expiration, as appropriate.
Schedule of Share-Based Compensation, RSUs, Activity	RSU activity under the 2015 Plan for the year ended March 31, 2019 was as follows: Number of Shares Weighted Average Grant Date Fair Value Intrinsic Value (in thousands) (1) (2) Unvested RSUs as of March 31, 2018 32,763 $ 23.06 $ 1,161 RSUs granted 571,570 $ 37.33 21,334 RSUs vested (23,867 ) $ 23.40 919 RSUs forfeited (30,613 ) $ 36.14 1,225 Unvested RSUs as of March 31, 2019 549,853 $ 37.15 $ 26,036 (1) As of March 31, 2019 and 2018, the intrinsic value of unvested shares was calculated based on the closing price of the Company’s ordinary shares on the NASDAQ Global Select Market on March 31, 2019 and 2018, respectively, multiplied by the number of unvested RSUs. (2) The intrinsic value of RSUs granted, vested and forfeited is calculated based on the closing price of the Company’s ordinary shares at the respective transaction dates multiplied by the number of RSUs.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Future Minimum Payments for Capital Leases, Facility Operating Leases and Data Center Operating Leases	Future minimum payments for our capital leases, facility operating leases (including Lexington MA – U.S. build-to-suit lease) and data center operating leases as of March 31, 2019 are as follows: Year Ending March 31, Capital Leases Facility Leases Data Centers 2020 $ 918 $ 10,649 $ 21,216 2021 1,102 15,186 17,427 2022 326 14,111 13,010 2023 — 13,825 2,774 2024 — 13,686 356 Thereafter — 59,502 — Total minimum lease payments $ 2,346 $ 126,959 $ 54,783 Less: Amount representing interest (121 ) Present value of capital lease obligations 2,225 Less: Current portion (844 ) Long-term portion of capital lease obligations $ 1,381

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	12 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Summary of Revenue by Geographic Area	The Company allocates, for the purpose of geographic data reporting, its revenue based upon the location of the contracting subsidiary. Total revenue by geographic area was as follows: Year ended March 31, 2019 2018 2017 United States $ 169,286 $ 128,503 $ 90,932 United Kingdom 103,900 81,720 61,188 South Africa 46,275 39,425 27,890 Other 20,916 12,249 6,553 Total revenue $ 340,377 $ 261,897 $ 186,563
Summary of Property and Equipment, Net by Geographic Location	Property and equipment, net by geographic location consists of the following: As of March 31, 2019 2018 United States (1) $ 62,455 $ 62,064 United Kingdom (2) 17,402 46,664 South Africa 6,170 6,512 Australia 3,481 3,953 Other 4,694 4,629 Total $ 94,202 $ 123,822 (1) Includes amounts capitalized related to the Company’s U.S. build-to-suit facility of $41.8 million and $39.4 million as of March 31, 2019 and 2018, respectively. (2) Includes amounts capitalized related to the Company’s U.K. build-to-suit facility of $31.2 million as of March 31, 2018. In March 2019, the Company derecognized the U.K. build-to-suit facility upon See Note 12 for further details

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Summary of Loss Before Income Taxes	Loss before income taxes consists of the following: Year ended March 31, 2019 2018 2017 United Kingdom $ (4,626 ) $ (15,939 ) $ (8,162 ) Foreign (374 ) 6,258 4,923 Loss before income taxes $ (5,000 ) $ (9,681 ) $ (3,239 )
Schedule of Provision for Income Taxes	The provision for income taxes in the accompanying consolidated financial statements is comprised of the following: As of March 31, 2019 2018 2017 Current tax expense: Domestic $ — $ — $ — Foreign 3,493 2,597 2,202 Total current tax expense 3,493 2,597 2,202 Deferred tax expense: Domestic (578 ) — — Foreign (914 ) 108 — Total deferred tax expense (1,492 ) 108 — Total provision for income taxes $ 2,001 $ 2,705 $ 2,202
Schedule of Reconciliation of Statutory Tax Rate to Effective Tax Rate	The reconciliation of the United Kingdom statutory tax rate to the Company’s effective tax rate included in the accompanying consolidated statements of operations is as follows: Year ended March 31, 2019 2018 2017 Tax at statutory rate 19.0 % 19.0 % 20.0 % U.S. state taxes, net of federal 31.1 14.1 (1.0 ) Foreign rate differential 26.3 36.8 (39.3 ) Meals and entertainment (11.4 ) (3.1 ) (7.4 ) Branch income / loss (0.6 ) 0.4 0.9 Share-based compensation 172.3 105.3 (4.0 ) Foreign exchange — — (24.8 ) Non-deductible interest expense — — (3.3 ) Tax credits 7.7 8.1 15.6 Unremitted earnings (3.8 ) (1.2 ) — Change in valuation allowance (249.9 ) (110.7 ) 124.7 Deferred tax true-ups (3.5 ) 8.4 (12.4 ) Tax reserves (4.9 ) (21.5 ) (117.7 ) Provision to return (0.1 ) 0.4 (0.7 ) Withholding taxes (2.6 ) (3.5 ) — Other foreign taxes — — (6.7 ) Non-deductible expenses (5.2 ) (2.4 ) (10.6 ) Deferred tax rate change (6.3 ) (77.8 ) (1.3 ) Acquisition related costs (7.6 ) — — Other (0.5 ) (0.2 ) — Effective Tax Rate (40.0 )% (27.9 )% (68.0 )%
Components of Deferred Tax Assets and (Liabilities)	Deferred tax assets and liabilities reflect the net tax effects of net operating loss carryovers and the temporary differences between the assets and liabilities carrying value for financial reporting and the amounts used for income tax purposes. T As of March 31, 2019 2018 Deferred tax assets: Net operating loss carryforwards $ 35,120 $ 24,159 Share-based compensation 5,687 2,760 Deferred revenue 1,761 2,237 Fixed assets 4,187 3,593 Lease liability 11,748 17,024 Accrued compensation 1,211 742 Accrued costs 401 1,362 Deferred rent 320 473 Income tax credits 1,833 1,151 Other 1,247 109 Gross deferred tax assets 63,515 53,610 Deferred tax liabilities: Prepaid expenses (219 ) (315 ) Fixed assets (13,855 ) (19,280 ) Unremitted earnings (320 ) (115 ) Intangible assets (4,818 ) — Capitalized commissions (7,606 ) — Other (387 ) — Gross deferred tax liabilities (27,205 ) (19,710 ) Valuation allowance (38,318 ) (34,008 ) Deferred tax (liabilities) assets, net $ (2,008 ) $ (108 )
Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows: Year ended March 31, 2019 2018 Beginning balance $ 6,164 $ 4,931 Additions based on tax positions related to current year 164 142 Additions for tax positions of prior years 231 1,444 Reductions due to change in foreign exchange rate (301 ) (353 ) Expiration of statutes of limitation (165 ) — Reductions due to settlements with tax authorities (77 ) — Ending balance $ 6,016 $ 6,164

Quarterly results of operatio_2

Quarterly results of operations data (unaudited) (Tables)	12 Months Ended
	Mar. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results of Operations Data	The following tables set forth our unaudited quarterly consolidated statements of operations for each of the eight quarters in the period ended March 31, 2019. We have prepared the quarterly consolidated statements of operations data on a basis consistent with the audited consolidated financial statements included elsewhere in this Annual Report on Form 10-K. In the opinion of management, the financial information reflects all adjustments, consisting only of normal recurring adjustments, which we consider necessary for a fair presentation of this data. This information should be read in conjunction with the audited consolidated financial statements and related notes included elsewhere in this Annual Report on Form 10-K. The results of historical periods are not necessarily indicative of the results to be expected for any future period. Quarter ended Mar 31, Dec 31, Sep 30, Jun 30, Mar 31, Dec 31, Sep 30, Jun 30, 2019 2018 2018 2018 2018 2017 2017 2017 (in thousands, except per share amounts) Revenue $ 92,193 $ 87,611 $ 82,169 $ 78,404 $ 73,401 $ 67,272 $ 63,066 $ 58,158 Gross profit 67,491 64,353 60,231 57,428 53,225 49,544 46,523 42,906 Income (loss) from operations 207 1,572 (909 ) (2,089 ) (4,206 ) (1,129 ) (508 ) (1,111 ) Net (loss) income (1,930 ) 458 (2,058 ) (3,471 ) (6,554 ) (2,593 ) (1,339 ) (1,900 ) Net (loss) income per ordinary share: Basic $ (0.03 ) $ 0.01 $ (0.03 ) $ (0.06 ) $ (0.11 ) $ (0.05 ) $ (0.02 ) $ (0.03 ) Diluted $ (0.03 ) $ 0.01 $ (0.03 ) $ (0.06 ) $ (0.11 ) $ (0.05 ) $ (0.02 ) $ (0.03 ) Weighted-average number of ordinary shares outstanding: Basic 60,733 60,141 59,800 59,175 58,264 57,505 57,027 56,292 Diluted 60,733 62,537 59,800 59,175 58,264 57,505 57,027 56,292

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2019USD ($)Customer$ / shares	Mar. 31, 2018USD ($)Customer$ / shares	Mar. 31, 2017USD ($)Customer$ / shares	May 15, 2019USD ($)	Apr. 01, 2018USD ($)
Summary Of Significant Accounting Policies [Line Items]
Unpaid purchases of property, equipment and capitalized software	$ 7,634,000	$ 7,977,000	$ 848,000
Accounts receivable	(80,953,000)	$ (65,392,000)
Aggregate fair value of investments	$ 10,000,000
Maximum percentage of revenue contribution from professional services and other revenue	5.00%	5.00%	5.00%
Upfront ingestion fee to be recognized over estimated customer benefit period	6 years
Accumulated deficit decreased	$ (83,632,000)	$ (106,507,000)		$ 29,900,000
Revenue recognized included in deferred revenue	118,700,000
Contracted revenue not yet recognized	$ 86,000,000
Number of customers representing more than 10% of accounts receivable | Customer	0	0
Number of customers representing more than 10% of revenue | Customer	0	0	0
Bad debt expenses	$ 200,000	$ 200,000	$ 100,000
Annual goodwill impairment test date	January 1st of each year
Impairment of long-lived assets	$ 0	1,712,000	0
Capitalized costs	0	0	0
Implementation costs capitalized	1,700,000
Advertising expenses incurred	12,500,000	12,400,000	$ 11,500,000
Uncertain tax positions impact to net tax provision	$ 0	$ 0
Weighted-average per share fair value of share options granted to employees | $ / shares	$ 16.48	$ 11.12	$ 8.65
2015 Employee Share Purchase Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected dividend rate	0.00%
Weighted-average per share fair value of share options granted to employees | $ / shares	$ 9.58	$ 6.41
Share Options [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected dividend rate	0.00%
Capitalized Software Video Production Costs [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated Useful Life (in years)	5 years
U.S. Treasury Securities [Member]
Summary Of Significant Accounting Policies [Line Items]
Investment maturity period	5 months
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Investment maturity period	2 years
Maximum [Member] | Corporate Securities [Member]
Summary Of Significant Accounting Policies [Line Items]
Investment maturity period	7 months
Maximum [Member] | Non-U.S. Government Securities [Member]
Summary Of Significant Accounting Policies [Line Items]
Investment maturity period	8 months
Minimum [Member] | Corporate Securities [Member]
Summary Of Significant Accounting Policies [Line Items]
Investment maturity period	1 month
Minimum [Member] | Non-U.S. Government Securities [Member]
Summary Of Significant Accounting Policies [Line Items]
Investment maturity period	3 months
ASU 2014-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization period of deferred contract costs	6 years
Payment of commissions related to contract renewals	$ 0
Accumulated deficit decreased					$ (76,631,000)
ASU 2014-09 [Member] | Adjustments Due to Adoption of Topic 606
Summary Of Significant Accounting Policies [Line Items]
(Decrease) to deferred revenue					(6,000,000)
Increase in deferred contract costs					23,800,000
Accumulated deficit decreased	$ 45,233,000				$ 29,876,000
Adjustment [Member]
Summary Of Significant Accounting Policies [Line Items]
Loss on disposal of fixed assets		$ (200,000)
Other non-cash items		200,000
Unpaid purchases of capitalized software licenses		(5,600,000)
Unpaid purchases of property, equipment and capitalized software		5,600,000
Provision for doubtful accounts		(100,000)
Accounts receivable		$ 100,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents due in 90 days or less, Cost	$ 137,576	$ 78,339
Cash and cash equivalents due in 90 days or less, Estimated fair value	137,576	78,339
Investments, Cost	35,913	58,960
Investments, Gross unrealized gains	37	9
Investments, Gross unrealized losses	(9)	(98)
Investments, Estimated fair value	35,941	58,871
Total cash, cash equivalents and investments, Cost	173,489	137,299
Total cash, cash equivalents and investments, Gross unrealized gains	37	9
Total cash, cash equivalents and investments, Gross unrealized Losses	(9)	(98)
Total cash, cash equivalents and investments, Estimated fair value	173,517	137,210
Cash and cash equivalents	137,576	78,339
U.S. Treasury Securities Due in One Year or Less [Member]
Cash And Cash Equivalents [Line Items]
Investments, Cost	1,993	2,995
Investments, Gross unrealized gains	1
Investments, Gross unrealized losses		(5)
Investments, Estimated fair value	1,994	2,990
Non-U.S. Government Securities Due in One Year or Less [Member]
Cash And Cash Equivalents [Line Items]
Investments, Cost	7,969	5,996
Investments, Gross unrealized gains	12	1
Investments, Gross unrealized losses		(1)
Investments, Estimated fair value	7,981	5,996
Corporate Securities Due in One Year or Less [Member]
Cash And Cash Equivalents [Line Items]
Investments, Cost	25,951	49,969
Investments, Gross unrealized gains	24	8
Investments, Gross unrealized losses	(9)	(92)
Investments, Estimated fair value	$ 25,966	$ 49,885

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Cumulative Effect of Changes to Balance Sheet (Detail) - USD ($) $ in Thousands	May 15, 2019	Mar. 31, 2019	Apr. 01, 2018	Mar. 31, 2018
Assets
Deferred contract costs, net		$ 8,140
Deferred contract costs, net of current portion		28,250
Liabilities
Deferred revenue		163,102		$ 123,057
Deferred revenue, net of current portion		12,472		18,045
Shareholders' equity
Accumulated deficit	$ 29,900	(83,632)		$ (106,507)
ASU 2014-09 [Member]
Assets
Deferred contract costs, net			$ 5,494
Deferred contract costs, net of current portion			18,339
Liabilities
Deferred revenue			122,540
Deferred revenue, net of current portion			12,519
Shareholders' equity
Accumulated deficit			(76,631)
ASU 2014-09 [Member] | Adjustments Due to Adoption of Topic 606
Assets
Deferred contract costs, net		8,140	5,494
Deferred contract costs, net of current portion		28,250	18,339
Liabilities
Deferred revenue		1,356	(517)
Deferred revenue, net of current portion		(8,864)	(5,526)
Shareholders' equity
Accumulated deficit		$ 45,233	$ 29,876

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Schedule of Quantitative Effect and Significant Changes Between ASC 606 and Legacy GAAP on Unaudited Condensed Consolidated Income Statement and Balance Sheet (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017	May 15, 2019	Apr. 01, 2018
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Revenues									$ 340,377	$ 261,897	$ 186,563
Operating expenses
Sales and marketing									(139,194)	(121,246)	(96,154)
Net loss	$ (1,930)	$ 458	$ (2,058)	$ (3,471)	$ (6,554)	$ (2,593)	$ (1,339)	$ (1,900)	(7,001)	(12,386)	$ (5,441)
Assets
Deferred contract costs, net	8,140								8,140
Deferred contract costs, net of current portion	28,250								28,250
Liabilities
Deferred revenue	163,102				123,057				163,102	123,057
Deferred revenue, net of current portion	12,472				18,045				12,472	18,045
Shareholders' equity
Accumulated deficit	(83,632)				$ (106,507)				(83,632)	$ (106,507)		$ 29,900
ASU 2014-09 [Member]
Assets
Deferred contract costs, net													$ 5,494
Deferred contract costs, net of current portion													18,339
Liabilities
Deferred revenue													122,540
Deferred revenue, net of current portion													12,519
Shareholders' equity
Accumulated deficit													(76,631)
ASU 2014-09 [Member] | Amounts without Adoption of Topic 606 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Revenues									338,829
Operating expenses
Sales and marketing									(153,003)
Net loss									(22,358)
Liabilities
Deferred revenue	161,746								161,746
Deferred revenue, net of current portion	21,336								21,336
Shareholders' equity
Accumulated deficit	(128,865)								(128,865)
ASU 2014-09 [Member] | Adjustments Due to Adoption of Topic 606
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Revenues									1,548
Operating expenses
Sales and marketing									(13,809)
Net loss									15,357
Assets
Deferred contract costs, net	8,140								8,140				5,494
Deferred contract costs, net of current portion	28,250								28,250				18,339
Liabilities
Deferred revenue	1,356								1,356				(517)
Deferred revenue, net of current portion	(8,864)								(8,864)				(5,526)
Shareholders' equity
Accumulated deficit	$ 45,233								$ 45,233				$ 29,876

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Additional Information (Detail 1)	Mar. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-04-01
Summary Of Significant Accounting Policies [Line Items]
Revenue, remaining performance obligation, percentage	51.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-04-01
Summary Of Significant Accounting Policies [Line Items]
Revenue, remaining performance obligation, percentage	46.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period	24 months

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Mar. 31, 2019
Buildings and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	10 years
Computer Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Computer Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	Lesser of asset life or lease term
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Dilutive Ordinary Shares Excluded from Calculation of Diluted Weighted-Average Shares Outstanding (Detail) - shares shares in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Share Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive ordinary share equivalents excluded from calculation of diluted weighted-average shares outstanding	6,209	6,230	8,681
Unvested RSUs [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive ordinary share equivalents excluded from calculation of diluted weighted-average shares outstanding	550	33	28

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Summary of Weighted-Average Assumption Utilized to Determine Fair Value of Option (Detail) - Share Options [Member] - $ / shares	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days	6 years 1 month 6 days
Risk-free interest rate	2.70%	2.20%	2.10%
Expected volatility	41.50%	39.80%	41.00%
Expected dividend yield	0.00%
Estimated grant date fair value per ordinary share	$ 37.15	$ 26.52	$ 20.22

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Summary of Assumptions Used in Black-Scholes Option Pricing Model to Estimate Fair Value of Shares Under the ESPP (Detail) - 2015 Employee Share Purchase Plan [Member] - $ / shares	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 months	6 months
Risk-free interest rate	2.30%	1.40%
Expected volatility	39.10%	29.90%
Expected dividend yield	0.00%
Grant date fair value per ordinary share	$ 36.69	$ 27.15

Balance Sheet Components - Prep

Balance Sheet Components - Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Prepaid Expense And Other Assets Current [Abstract]
Prepaid expenses	$ 11,259	$ 10,766
Lease incentive due from landlord	8,900
Research and development investment tax credits	3,862	3,353
Other current assets	1,850	1,183
Total prepaid expenses and other current assets	$ 25,871	$ 15,302

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 173,379	$ 189,849
Less: Accumulated depreciation and amortization	(79,177)	(66,027)
Property and equipment, net	94,202	123,822
Buildings and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	47,001	75,165
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	112,277	102,821
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	8,166	6,504
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,590	4,187
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,345	$ 1,172

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Property and Equipment, Net (Parenthetical) (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 173,379	$ 189,849
Less: Accumulated depreciation and amortization	(79,177)	(66,027)
Property and equipment, net	94,202	123,822
Buildings and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Less: Accumulated depreciation	(5,164)	(753)
Construction costs capitalized related to build-to-suit facilities	41,837	74,412
Property and equipment, gross	47,001	75,165
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,754	4,713
Less: Accumulated depreciation and amortization	(2,228)	(990)
Property and equipment, net	2,526	3,723
United States [Member]
Property, Plant and Equipment [Line Items]
Construction costs capitalized	41,800	39,400
Property and equipment, net	62,455	62,064
United States [Member] | Buildings and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Construction costs capitalized	47,001	43,925
United Kingdom [Member]
Property, Plant and Equipment [Line Items]
Construction costs capitalized		31,200
Property and equipment, net	$ 17,402	46,664
United Kingdom [Member] | Buildings and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Construction costs capitalized		$ 31,240

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 173,379	$ 189,849
Depreciation and amortization	25,200	17,500	$ 11,800
Depreciation and amortization related to property and equipment acquired under capital leases	1,200	900	$ 100
Building Improvements [Member] | United States [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,200	$ 4,500

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Payables And Accruals [Abstract]
Accrued payroll and related benefits	$ 21,198	$ 15,325
Accrued taxes payable	5,305	4,029
Construction financing lease obligation	2,670	2,421
Restructuring liability	49	851
Other accrued expenses	15,087	11,252
Total accrued expenses and other current liabilities	$ 44,309	$ 33,878

Balance Sheet Components - Othe

Balance Sheet Components - Other Non-current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Other Liabilities Disclosure [Abstract]
Deferred rent	$ 10,218	$ 840
Restructuring liability		74
Other non-current liabilities	5,363	4,040
Total other non-current liabilities	$ 15,581	$ 4,954

Restructuring - Additional Info

Restructuring - Additional Information (Detail) - Watertown, MA Corporate Office [Member] - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Mar. 31, 2018
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 0.2	$ 0.8
Fair value of the restructuring liability		1.1
Deferred rent liabilities		$ 0.3

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 25, 2019	Jul. 31, 2018	Jul. 09, 2018	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Business Acquisition [Line Items]
Net of cash acquired				$ 115,673	$ 1,381	$ 5,574
Goodwill				$ 107,575	$ 5,631	$ 5,363
Developed Technology [Member]
Business Acquisition [Line Items]
Estimated Useful Life (in years)				9 years	9 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Estimated Useful Life (in years)				6 years	6 years
Solebit Labs Ltd. [Member]
Business Acquisition [Line Items]
Business acquisition, agreement date of acquisition		Jul. 31, 2018
Ownership interest before acquisition		1.50%
Fair value of previously held asset		$ 800		$ 828
Preliminary purchase price		96,500		96,496
Cash payment		95,700
Purchase price consideration held in escrow		$ 8,400
Business combination, indemnification period		1 year
Acquisition-related expenses				1,000
Net of cash acquired				85,258
Estimated fair values of identifiable intangible assets, amount		$ 16,964		16,964
Goodwill				74,469
Solebit Labs Ltd. [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, amount		$ 16,689
Estimated Useful Life (in years)		10 years
Solebit Labs Ltd. [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, amount		$ 235
Estimated Useful Life (in years)		7 years
Solebit Labs Ltd. [Member] | Foreign Exchange (Expense) Income and Other Net [Member]
Business Acquisition [Line Items]
Gain recognized before acquisition		$ 300
Ataata [Member]
Business Acquisition [Line Items]
Cash payment			$ 23,200
Acquisition-related expenses				500
Business acquisition, effective date of acquisition			Jul. 9, 2018
Net of cash acquired			$ 1,900
Estimated fair values of identifiable intangible assets, amount			1,500
Goodwill			22,600
Ataata [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, amount			$ 1,400
Estimated Useful Life (in years)			10 years
Ataata [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, amount			$ 100
Estimated Useful Life (in years)			6 years
Simply Migrate [Member]
Business Acquisition [Line Items]
Cash payment	$ 7,200
Acquisition-related expenses				$ 600
Business acquisition, effective date of acquisition	Jan. 25, 2019
Net of cash acquired	$ 100
Estimated fair values of identifiable intangible assets, amount	3,300
Goodwill	$ 4,300
Simply Migrate [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Estimated Useful Life (in years)	8 years

Acquisitions - Summary of Preli

Acquisitions - Summary of Preliminary Purchase Price Allocation (Detail) - USD ($) $ in Thousands	Jul. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Preliminary purchase consideration:
Total cash paid, net of acquired cash		$ 115,673	$ 1,381	$ 5,574
Fair value of assets acquired and liabilities assumed:
Goodwill		107,575	$ 5,631	$ 5,363
Solebit Labs Ltd. [Member]
Preliminary purchase consideration:
Total cash paid, net of acquired cash		85,258
Cash and cash equivalents acquired		10,410
Fair value of previously held asset	$ 800	828
Total preliminary purchase price consideration	96,500	96,496
Fair value of assets acquired and liabilities assumed:
Cash and cash equivalents acquired		10,410
Prepaid expenses and other current assets		76
Intangible assets	$ 16,964	16,964
Goodwill		74,469
Total assets acquired		101,919
Accounts payable		(18)
Accrued expenses and other current liabilities		(2,345)
Deferred revenue		(663)
Other non-current liabilities		(2,397)
Total fair value of assets acquired and liabilities assumed		$ 96,496

Acquisitions - Summary of Estim

Acquisitions - Summary of Estimated Fair Values and Useful Lives of Identifiable Intangible (Detail) - USD ($) $ in Thousands	Jul. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Developed Technology [Member]
Business Acquisition [Line Items]
Estimated Useful Life (in years)		9 years	9 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Estimated Useful Life (in years)		6 years	6 years
Trade Names [Member]
Business Acquisition [Line Items]
Estimated Useful Life (in years)		1 year
Solebit Labs Ltd. [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, Amount	$ 16,964	$ 16,964
Solebit Labs Ltd. [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, Amount	$ 16,689
Estimated Useful Life (in years)	10 years
Solebit Labs Ltd. [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, Amount	$ 235
Estimated Useful Life (in years)	7 years
Solebit Labs Ltd. [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, Amount	$ 40
Estimated Useful Life (in years)	1 year

Acquisitions - Summary of Pro F

Acquisitions - Summary of Pro Forma Financial Information (unaudited) (Detail) - Solebit Labs Ltd. [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Revenue	$ 340,824	$ 262,773
Net loss	$ (7,729)	$ (17,359)
Basic net loss per share	$ (0.13)	$ (0.30)
Diluted net loss per share	$ (0.13)	$ (0.30)
Weighted average number of ordinary shares outstanding
Basic and diluted	59,960	57,269

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Goodwill Balance (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Goodwill Roll Forward
Beginning balance	$ 5,631	$ 5,363
Goodwill acquired	101,381	226
Effect of foreign exchange rates	563	42
Ending balance	$ 107,575	$ 5,631

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross Carrying Value	$ 36,519	$ 10,825
Accumulated Amortization	(5,896)	(1,563)
Finite-Lived Intangible Assets, Net Carrying Value	30,623	9,262
Intangible Assets, Gross Carrying Value		11,382
Intangible assets, net	$ 30,623	9,819
In-Process Research and Development [Member]
Finite Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets, Net Carrying Value		$ 557
Developed Technology [Member]
Finite Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Life (in years)	9 years	9 years
Finite-Lived Intangible Assets, Gross Carrying Value	$ 23,577	$ 1,546
Accumulated Amortization	(1,707)	(213)
Finite-Lived Intangible Assets, Net Carrying Value	$ 21,870	$ 1,333
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Life (in years)	6 years	6 years
Finite-Lived Intangible Assets, Gross Carrying Value	$ 455	$ 108
Accumulated Amortization	(73)	(21)
Finite-Lived Intangible Assets, Net Carrying Value	$ 382	$ 87
Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Life (in years)	1 year
Finite-Lived Intangible Assets, Gross Carrying Value	$ 56
Accumulated Amortization	(34)
Finite-Lived Intangible Assets, Net Carrying Value	$ 22
Capitalized Software [Member]
Finite Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Life (in years)	3 years	3 years
Finite-Lived Intangible Assets, Gross Carrying Value	$ 12,431	$ 9,171
Accumulated Amortization	(4,082)	(1,329)
Finite-Lived Intangible Assets, Net Carrying Value	$ 8,349	$ 7,842

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Schedule of Intangible Assets (Parenthetical) (Detail) $ in Millions	Mar. 31, 2019USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Capitalized costs related to video production costs	$ 0.4

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense	$ 4.8	$ 1.5	$ 0.1

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets - Schedule of Future Estimated Amortization Expense of Acquired Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net Carrying Value	$ 30,623	$ 9,262
Purchased Intangible Assets [Member]
Finite Lived Intangible Assets [Line Items]
2020	2,582
2021	2,560
2022	2,560
2023	2,560
Thereafter	12,012
Finite-Lived Intangible Assets, Net Carrying Value	22,274
Capitalized Software [Member]
Finite Lived Intangible Assets [Line Items]
2020	3,522
2021	2,790
2022	1,420
2023	528
Thereafter	89
Finite-Lived Intangible Assets, Net Carrying Value	$ 8,349	$ 7,842

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)	Mar. 31, 2019	Mar. 31, 2018
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets measured at fair value on a recurring basis	$ 44,289,000	$ 69,014,000
Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets measured at fair value on a recurring basis	0	0
Liabilities measured at fair value on a recurring basis	$ 0	$ 0

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Financial Assets Measured and Recorded at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Assets:
Total assets	$ 44,289	$ 69,014
Money Market Funds [Member]
Assets:
Total assets	8,348	10,143
U.S. Treasury Securities [Member]
Assets:
Total assets	1,994	2,990
Non-U.S. Government Securities [Member]
Assets:
Total assets	7,981	5,996
Corporate Securities [Member]
Assets:
Total assets	25,966	49,885
Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs) [Member]
Assets:
Total assets	8,348	10,143
Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs) [Member] | Money Market Funds [Member]
Assets:
Total assets	8,348	10,143
Significant Other Observable Inputs (Level 2 Inputs) [Member]
Assets:
Total assets	35,941	58,871
Significant Other Observable Inputs (Level 2 Inputs) [Member] | U.S. Treasury Securities [Member]
Assets:
Total assets	1,994	2,990
Significant Other Observable Inputs (Level 2 Inputs) [Member] | Non-U.S. Government Securities [Member]
Assets:
Total assets	7,981	5,996
Significant Other Observable Inputs (Level 2 Inputs) [Member] | Corporate Securities [Member]
Assets:
Total assets	$ 25,966	$ 49,885

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)	Sep. 30, 2018	Jul. 23, 2018	Mar. 31, 2019
Senior Secured Term Loan [Member]
Debt Instrument [Line Items]
Debt issuance costs			$ 1,269,000
Outstanding borrowings			98,125,000
Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Outstanding borrowings			0
Amount available under credit facility			46,100,000
Senior Secured Revolving Credit Facility [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Outstanding borrowings			3,900,000
Senior Secured Revolving Credit Facility [Member] | Other Assets [Member]
Debt Instrument [Line Items]
Debt issuance costs			$ 600,000
Credit Agreement with Certain Lenders [Member]
Debt Instrument [Line Items]
Credit facility term		5 years
Credit facility maturity date		Jul. 23, 2023
Credit facility outstanding debt		$ 0
Credit Agreement with Certain Lenders [Member] | LIBOR Plus [Member]
Debt Instrument [Line Items]
Credit facility current interest rate			1.625%
Credit Agreement with Certain Lenders [Member] | Minimum [Member] | LIBOR Plus [Member]
Debt Instrument [Line Items]
Credit facility interest rate		1.375%
Credit Agreement with Certain Lenders [Member] | Maximum [Member] | LIBOR Plus [Member]
Debt Instrument [Line Items]
Credit facility interest rate		1.875%
Credit Agreement with Certain Lenders [Member] | Senior Secured Term Loan [Member]
Debt Instrument [Line Items]
Credit facility amount		$ 100,000,000
Credit Agreement with Certain Lenders [Member] | Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility amount		50,000,000
Credit Agreement with Certain Lenders [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt issuance costs		$ 2,300,000
Credit Agreement with Certain Lenders [Member] | Senior Secured Term Loan and Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility financial covenants ratio commencement date	Sep. 30, 2018
Consolidated interest expense ratio	300.00%
Credit facility financial covenants			The Credit Agreement has financial covenants that require the Company to maintain a Consolidated Secured Leverage Ratio (as defined in the Credit Agreement), commencing on September 30, 2018, of not more than 3.00 to 1.00 for the four consecutive fiscal quarter period ending on the last day of each fiscal quarter (the Reference Period), with a step-up to 3.50 to 1.00 for any four-quarter period in which the Company consummates a permitted acquisition having an aggregate purchase price in excess of $25.0 million. The Company must also maintain a Consolidated Interest Expense Ratio (as defined in the Credit Agreement) of 3.00 to 1.00 commencing on September 30, 2018 and for each Reference Period thereafter.
Credit Agreement with Certain Lenders [Member] | Senior Secured Term Loan and Senior Secured Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Secured leverage ratio	300.00%
Aggregate purchase price of acquisition	$ 25,000,000
Credit Agreement with Certain Lenders [Member] | Senior Secured Term Loan and Senior Secured Revolving Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Secured leverage ratio	350.00%

Debt - Schedule of Future Minim

Debt - Schedule of Future Minimum Principal Payment Obligations (Detail) $ in Thousands	Mar. 31, 2019USD ($)
Debt Instrument [Line Items]
Less: Current portion of long-term debt	$ (4,059)
Long-term debt	92,797
Senior Secured Term Loan [Member]
Debt Instrument [Line Items]
2020	4,375
2021	6,875
2022	9,375
2023	10,000
2024	67,500
Total minimum debt payments	98,125
Less: Debt issuance costs	(1,269)
Less: Current portion of long-term debt	(4,059)
Long-term debt	$ 92,797

Shareholders' Equity - Schedule

Shareholders' Equity - Schedule of Ordinary Share Reserved for Future Issuance (Detail) - shares	Mar. 31, 2019	Mar. 31, 2018
Class of Stock [Line Items]
Options outstanding under share option plans	6,208,964	6,229,860
Unvested RSUs	549,853
Total authorized ordinary shares reserved for future issuance	16,802,734
ESPP [Member]
Class of Stock [Line Items]
Total authorized ordinary shares reserved for future issuance	905,114
2015 Plan [Member]
Class of Stock [Line Items]
Options and awards available for future grant under the 2015 Plan	9,138,803

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail) $ in Thousands	12 Months Ended
	Mar. 31, 2019USD ($)CompensationPlanInstallmentshares	Mar. 31, 2018USD ($)shares	Mar. 31, 2017USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share-based compensation plans | CompensationPlan	4
Ordinary shares reserved for future issuance | shares	16,802,734
Employee share option agreements, modification expense	$ 3,200	$ 500	$ 3,000
Total intrinsic value of options exercised	66,400	74,200	24,800
Proceeds from exercises of share-based awards	21,400	15,600	4,500
Share-based compensation expense recognized	25,954	$ 11,734	$ 10,294
Service-Based Vesting Conditions [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share-based compensation expense	$ 44,600
Unrecognized share-based compensation expense, net of estimated forfeiture, period for recognition	2 years 9 months 29 days
Unvested RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share-based compensation expense	$ 16,500
Unrecognized share-based compensation expense, net of estimated forfeiture, period for recognition	3 years 1 month 20 days
Unvested RSUs [Member] | Non-Employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, vesting period	3 years
Unvested RSUs [Member] | Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vesting installment for equity granted | Installment	4
2015 Plan [Member] | Share Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ordinary shares reserved for future issuance | shares	5,500,000
Increase in number of shares reserved and available for issuance, percentage	5.00%
Share-based compensation arrangement by share-based payment award, term	10 years
Share-based compensation arrangement by share-based payment award, vesting period	4 years
2015 Employee Share Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, term	6 months
Ordinary shares reserved and authorized for issuance | shares	1,100,000
Authorized payroll deductions percentage	10.00%
Percentage of fair market value of shares to be considered as share price	85.00%
Number of shares issued in connection with ESPP | shares	130,000	64,000
Cash proceeds from shares issued in connection with ESPP	$ 3,300	$ 1,400
Share-based compensation expense recognized	$ 1,300	$ 700
2015 Employee Share Purchase Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized payroll deductions percentage	1.00%

Share-Based Compensation - Shar

Share-Based Compensation - Share-Based Compensation Expense Recognized in Statements of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	$ 25,954	$ 11,734	$ 10,294
Cost of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	1,684	1,053	1,353
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	6,199	2,555	1,873
Sales and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	7,856	4,477	4,719
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	$ 10,215	$ 3,649	$ 2,349

Share-Based Compensation - Sche

Share-Based Compensation - Schedule of Share-Based Compensation, Stock Options, Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Awards, Beginning balance	6,229,860
Number of Awards, Options granted	2,491,548
Number of Awards, Options exercised	(2,054,813)
Number of Awards, Options forfeited and cancelled	(457,631)
Number of Awards, Ending balance	6,208,964	6,229,860
Number of Awards, Exercisable	2,054,822
Weighted Average Exercise Price, Beginning balance	$ 13.78
Weighted Average Exercise Price, Options granted	37.15
Weighted Average Exercise Price, Options exercised	10.39
Weighted Average Exercise Price, Options forfeited and cancelled	25.61
Weighted Average Exercise Price, Ending balance	23.47	$ 13.78
Weighted Average Exercise Price Exercisable	$ 11.56
Weighted Average Remaining Contractual Term, Outstanding	7 years 6 months 29 days	7 years 4 months 24 days
Weighted Average Remaining Contractual Term, Exercisable	5 years 8 months 1 day
Aggregate Intrinsic Value, Outstanding	$ 148,313	$ 134,859
Aggregate Intrinsic Value, Exercisable	$ 73,538

Share-Based Compensation - Sc_2

Share-Based Compensation - Schedule of Share-Based Compensation, RSUs, Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Shares Unvested, RSUs Begining balance
Number of Shares, Unvested RSUs, Ending balance	549,853
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Shares Unvested, RSUs Begining balance	32,763
Number of Shares, RSUs granted	571,570
Number of Shares, RSUs vested	(23,867)
Number of Shares, RSUs forfeited	(30,613)
Number of Shares, Unvested RSUs, Ending balance	549,853
Weighted Average Grant Date Fair Value, Unvested RSUs, Beginning balance | $ / shares	$ 23.06
Weighted Average Grant Date Fair Value, RSUs granted | $ / shares	37.33
Weighted Average Grant Date Fair Value, RSUs vested | $ / shares	23.40
Weighted Average Grant Date Fair Value, RSUs forfeited | $ / shares	36.14
Weighted Average Grant Date Fair Value, Unvested RSUs, Ending balance | $ / shares	$ 37.15
Intrinsic Value, Unvested RSUs | $	$ 1,161
Intrinsic Value, RSUs granted | $	21,334
Intrinsic Value, RSUs vested | $	919
Intrinsic Value, RSUs forfeited | $	1,225
Intrinsic Value, Unvested RSUs | $	$ 26,036

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Feb. 28, 2017USD ($)ft²Option	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)ft²Gbp_Per_Square_Foot	Mar. 31, 2017USD ($)
Commitments And Contingencies [Line Items]
Rent expenses				$ 5,300	$ 4,800	$ 3,200
Letters of credit outstanding relating to operating leases			$ 3,900	3,900	3,800
Future minimum sublease rental income under non-cancelable subleases			600	600
Interest expense on lease financial obligation				1,900	500
Financial obligation of future estimate commitments, Principal			36,500	36,500
Financial obligation of future estimate commitments, interest			10,000	10,000
General and administrative			1,000	53,759	$ 36,989	$ 27,875
191 Spring Lease [Member]
Commitments And Contingencies [Line Items]
Letters of credit outstanding relating to operating leases	$ 1,300		1,300	$ 1,300
Area of office space leased | ft²	79,145
Lease term	10 years
Lease commenced period	January 2018
Number of renewal options | Option	2
Lease contract additional extension option				The Company has the option to extend the 191 Spring Lease for two successive five-year terms.
Lease renewal term	5 years
191 Spring Lease [Member] | Maximum [Member]
Commitments And Contingencies [Line Items]
Allowance for normal tenant improvements	$ 5,500
U.K. Leases [Member]
Commitments And Contingencies [Line Items]
Derecognized the build-to-suit asset and liability			$ 56,800	$ 56,800
U.K. Leases [Member] | United Kingdom [Member]
Commitments And Contingencies [Line Items]
Area of office space leased | ft²					113,000
Lease term					15 years
Price per square foot per year | Gbp_Per_Square_Foot					56.50
Lease maturity term					2029-03
Lease an option to opt-out term					10 years
Lease, option to extend description				In the event the Company does not elect its option to opt-out, the Company has the option to extend the U.K. Leases for two successive five-year terms.
U.K. Leases [Member] | United Kingdom [Member] | Scenario Forecast [Member]
Commitments And Contingencies [Line Items]
Lease incentive free rent period		1 year
Cash inducement payable		$ 8,900

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Payments for Capital Leases, Facility Operating Leases and Data Center Operating Leases (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Capital Leases Operating Leases And Data Centers [Line Items]
Capital Leases, 2020	$ 918
Capital Leases, 2021	1,102
Capital Leases, 2022	326
Total minimum lease payments	2,346
Less: Amount representing interest	(121)
Present value of capital lease obligations	2,225
Less: Current portion	(844)	$ (1,125)
Long-term capital lease obligations	1,381	$ 2,390
Facility Leases, 2020	10,649
Facility Leases, 2021	15,186
Facility Leases, 2022	14,111
Facility Leases, 2023	13,825
Facility Leases, 2024	13,686
Facility Leases, Thereafter	59,502
Total minimum lease payments	126,959
Data Centers [Member]
Capital Leases Operating Leases And Data Centers [Line Items]
Data Centers, 2020	21,216
Data Centers, 2021	17,427
Data Centers, 2022	13,010
Data Centers, 2023	2,774
Data Centers, 2024	356
Total minimum lease payments	$ 54,783

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Employee Benefits And Share Based Compensation [Abstract]
Matching contributions to 401(k) plan by employer	$ 1,200,000	$ 0
Additional contribution percentage by the company	3.00%
Contribution expense	$ 1,500,000	$ 500,000

Segment and Geographic Inform_3

Segment and Geographic Information - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2019Segment
Segment Reporting [Abstract]
Number of operating segment	1

Segment and Geographic Inform_4

Segment and Geographic Information - Summary of Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 340,377	$ 261,897	$ 186,563
United States [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	169,286	128,503	90,932
United Kingdom [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	103,900	81,720	61,188
South Africa [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	46,275	39,425	27,890
Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 20,916	$ 12,249	$ 6,553

Segment and Geographic Inform_5

Segment and Geographic Information - Summary of Property and Equipment, Net by Geographic Location (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	$ 94,202	$ 123,822
United States [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	62,455	62,064
United Kingdom [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	17,402	46,664
Australia [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	3,481	3,953
South Africa [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	6,170	6,512
Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	$ 4,694	$ 4,629

Segment and Geographic Inform_6

Segment and Geographic Information - Summary of Property and Equipment, Net by Geographic Location (Parenthetical) (Detail) - USD ($) $ in Millions	Mar. 31, 2019	Mar. 31, 2018
United States [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Amount capitalized related to build-to-suit facility	$ 41.8	$ 39.4
United Kingdom [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Amount capitalized related to build-to-suit facility		$ 31.2

Income Taxes - Summary of Loss

Income Taxes - Summary of Loss Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
United Kingdom	$ (4,626)	$ (15,939)	$ (8,162)
Foreign	(374)	6,258	4,923
Loss before income taxes	$ (5,000)	$ (9,681)	$ (3,239)

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Domestic	$ 0	$ 0	$ 0
Foreign	3,493	2,597	2,202
Total current tax expense	3,493	2,597	2,202
Domestic	(578)	0	0
Foreign	(914)	108	0
Total deferred tax expense	(1,492)	108	0
Total provision for income taxes	$ 2,001	$ 2,705	$ 2,202

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Statutory Tax Rate to Effective Tax Rate (Detail)	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Tax at statutory rate	19.00%	19.00%	20.00%
U.S. state taxes, net of federal	31.10%	14.10%	(1.00%)
Foreign rate differential	26.30%	36.80%	(39.30%)
Meals and entertainment	(11.40%)	(3.10%)	(7.40%)
Branch income / loss	(0.60%)	0.40%	0.90%
Share-based compensation	172.30%	105.30%	(4.00%)
Foreign exchange			(24.80%)
Non-deductible interest expense			(3.30%)
Tax credits	7.70%	8.10%	15.60%
Unremitted earnings	(3.80%)	(1.20%)
Change in valuation allowance	(249.90%)	(110.70%)	124.70%
Deferred tax true-ups	(3.50%)	8.40%	(12.40%)
Tax reserves	(4.90%)	(21.50%)	(117.70%)
Provision to return	(0.10%)	0.40%	(0.70%)
Withholding taxes	(2.60%)	(3.50%)
Other foreign taxes			(6.70%)
Non-deductible expenses	(5.20%)	(2.40%)	(10.60%)
Deferred tax rate change	(6.30%)	(77.80%)	(1.30%)
Acquisition related costs	(7.60%)
Other	(0.50%)	(0.20%)
Effective Tax Rate	(40.00%)	(27.90%)	(68.00%)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Income Taxes [Line Items]
Tax at statutory rate	19.00%	19.00%	20.00%
Additional tax benefit	$ 1,000,000
Liabilities for uncertain tax positions	6,000,000	$ 6,200,000
Liabilities for uncertain tax positions, if recognized having impact on effective tax rate	0	$ 0
Unremitted foreign earnings	24,900,000
Unremitted foreign earnings for income taxes have been provided	10,000,000
Unremitted foreign earnings for income taxes have not been provided	14,900,000
U. K. [Member] | Domestic Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	57,400,000
Net operating loss carryforwards	1,100,000
U.S. Federal [Member] | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	78,600,000
U.S. State [Member] | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 54,600,000
Net operating loss carryforwards, expiration year	2039
Australian [Member] | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 23,900,000
German [Member] | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	9,900,000
Israeli [Member] | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	3,300,000
Net operating loss carryforwards	$ 600,000
Minimum [Member] | Israeli [Member] | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Tax credit carryforward, expiration year	2023
Maximum [Member] | Israeli [Member] | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Tax credit carryforward, expiration year	2024
Expires at Various Dates [Member] | U.S. Federal [Member] | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 32,500,000
Net operating loss carryforwards, expiration year	2037
Do Not Expire [Member] | U.S. Federal [Member] | Foreign Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 46,100,000
ASU 2016-09 [Member]
Income Taxes [Line Items]
Net increase in valuation allowance	$ 4,300,000

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and (Liabilities) (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 35,120	$ 24,159
Share-based compensation	5,687	2,760
Deferred revenue	1,761	2,237
Fixed assets	4,187	3,593
Lease liability	11,748	17,024
Accrued compensation	1,211	742
Accrued costs	401	1,362
Deferred rent	320	473
Income tax credits	1,833	1,151
Other	1,247	109
Gross deferred tax assets	63,515	53,610
Deferred tax liabilities:
Prepaid expenses	(219)	(315)
Fixed assets	(13,855)	(19,280)
Unremitted earnings	(320)	(115)
Intangible assets	(4,818)
Capitalized commissions	(7,606)
Other	(387)
Gross deferred tax liabilities	(27,205)	(19,710)
Valuation allowance	(38,318)	(34,008)
Deferred tax (liabilities) assets, net	$ (2,008)	$ (108)

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Beginning balance	$ 6,164	$ 4,931
Additions based on tax positions related to current year	164	142
Additions for tax positions of prior years	231	1,444
Reductions due to change in foreign exchange rate	(301)	(353)
Expiration of statutes of limitation	(165)
Reductions due to settlements with tax authorities	(77)
Ending balance	$ 6,016	$ 6,164

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - $ / shares	Apr. 01, 2019	Mar. 31, 2019
Subsequent Event [Line Items]
Options granted		2,491,548
Share Options [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Options granted	1,100,000
Grant date fair value of options	$ 21.13
RSUs [Member]
Subsequent Event [Line Items]
Number of Shares, Restricted share units granted		571,570
RSUs [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Number of Shares, Restricted share units granted	600,000
Grant date fair value of restricted share units	$ 47.23

Quarterly Results of Operatio_3

Quarterly Results of Operations Data (Unaudited) - Summary of Quarterly Results of Operations Data (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 92,193	$ 87,611	$ 82,169	$ 78,404	$ 73,401	$ 67,272	$ 63,066	$ 58,158
Gross profit	67,491	64,353	60,231	57,428	53,225	49,544	46,523	42,906	$ 249,503	$ 192,198	$ 136,249
Income (loss) from operations	207	1,572	(909)	(2,089)	(4,206)	(1,129)	(508)	(1,111)	(1,219)	(6,954)	(10,373)
Net (loss) income	$ (1,930)	$ 458	$ (2,058)	$ (3,471)	$ (6,554)	$ (2,593)	$ (1,339)	$ (1,900)	$ (7,001)	$ (12,386)	$ (5,441)
Net loss per ordinary share
Basic	$ (0.03)	$ 0.01	$ (0.03)	$ (0.06)	$ (0.11)	$ (0.05)	$ (0.02)	$ (0.03)
Diluted	$ (0.03)	$ 0.01	$ (0.03)	$ (0.06)	$ (0.11)	$ (0.05)	$ (0.02)	$ (0.03)
Weighted-average number of ordinary shares outstanding
Basic	60,733	60,141	59,800	59,175	58,264	57,505	57,027	56,292
Diluted	60,733	62,537	59,800	59,175	58,264	57,505	57,027	56,292