Mimecast (MIME) 10-Q 3 Feb 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Dec. 31, 2021	Jan. 27, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Trading Symbol	MIME
Title of 12(b) Security	Ordinary Shares, par value $0.012 per share
Security Exchange Name	NASDAQ
Entity Registrant Name	MIMECAST LIMITED
Entity Central Index Key	0001644675
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		66,922,342
Entity Shell Company	false
Document Quarterly Report	true
Document Transition Report	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity File Number	001-37637
Entity Incorporation, State or Country Code	Y9
Entity Tax Identification Number	00-0000000
Entity Address, Address Line One	1 Finsbury Avenue
Entity Address, City or Town	London
Entity Address, Country	GB
Entity Address, Postal Zip Code	EC2M 2PF
City Area Code	781
Local Phone Number	996-5340

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Current assets
Cash and cash equivalents	$ 416,173	$ 292,949
Accounts receivable, net	120,071	114,280
Deferred contract costs, net	18,667	16,165
Prepaid expenses and other current assets	20,729	20,031
Total current assets	575,640	443,425
Property and equipment, net	91,066	92,891
Operating lease right-of-use assets	113,810	128,063
Intangible assets, net	40,944	43,193
Goodwill	180,600	173,952
Deferred contract costs, net of current portion	53,577	50,086
Other assets	3,248	3,097
Total assets	1,058,885	934,707
Current liabilities
Accounts payable	7,088	10,487
Accrued expenses and other current liabilities	64,067	54,676
Deferred revenue	253,345	237,749
Current portion of finance lease obligations	429	323
Current portion of operating lease liabilities	29,703	33,447
Current portion of long-term debt	9,738	9,090
Total current liabilities	364,370	345,772
Deferred revenue, net of current portion	10,624	12,936
Operating lease liabilities	98,969	112,316
Long-term debt	69,867	94,671
Other non-current liabilities	7,171	8,143
Total liabilities	551,001	573,838
Commitments and contingencies (Note 13)
Shareholders' equity
Ordinary shares, $0.012 par value, 300,000,000 shares authorized; 66,907,431 and 64,562,222 shares issued and outstanding as of December 31, 2021 and March 31, 2021, respectively	803	775
Additional paid-in capital	508,400	408,249
Accumulated deficit	(12,442)	(53,915)
Accumulated other comprehensive income	11,123	5,760
Total shareholders' equity	507,884	360,869
Total liabilities and shareholders' equity	$ 1,058,885	$ 934,707

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Dec. 31, 2021	Mar. 31, 2021
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	66,907,431	64,562,222
Ordinary shares, outstanding	66,907,431	64,562,222

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Revenue	$ 151,599	$ 129,636	$ 441,381	$ 367,505
Cost of revenue	34,408	31,572	101,433	89,783
Gross profit	117,191	98,064	339,948	277,722
Operating expenses
Research and development	26,305	25,408	83,025	70,497
Sales and marketing	49,738	45,187	146,775	133,224
General and administrative	24,199	16,649	60,373	50,400
Total operating expenses	100,242	87,244	290,173	254,121
Income from operations	16,949	10,820	49,775	23,601
Other income (expense)
Interest income	82	261	351	612
Interest expense	(465)	(578)	(1,535)	(2,251)
Foreign exchange (expense) income and other, net	(1,043)	1,441	(2,234)	4,365
Total other income (expense), net	(1,426)	1,124	(3,418)	2,726
Income before income taxes	15,523	11,944	46,357	26,327
Provision for income taxes	1,705	1,155	4,884	2,350
Net income	$ 13,818	$ 10,789	$ 41,473	$ 23,977
Net income per ordinary share
Basic	$ 0.21	$ 0.17	$ 0.63	$ 0.38
Diluted	$ 0.20	$ 0.16	$ 0.60	$ 0.37
Weighted-average number of ordinary shares outstanding
Basic	66,575	63,987	65,921	63,509
Diluted	70,133	66,023	68,767	65,419

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 13,818	$ 10,789	$ 41,473	$ 23,977
Other comprehensive income:
Change in foreign currency translation adjustment	3,006	15,775	5,363	21,766
Total other comprehensive income	3,006	15,775	5,363	21,766
Comprehensive income	$ 16,824	$ 26,564	$ 46,836	$ 45,743

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Ordinary Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Mar. 31, 2020	$ 232,055	$ 754	$ 325,808	$ (83,660)	$ (10,847)
Beginning balance, Shares at Mar. 31, 2020		62,792,000
Net income	23,977			23,977
Foreign currency translation adjustment	21,766				21,766
Issuance of ordinary shares upon exercise of share options	24,697	$ 14	24,683
Issuance of ordinary shares upon exercise of share options, Shares		1,160,000
Share-based compensation	41,183		41,183
ESPP purchases	6,416	$ 2	6,414
ESPP purchases, Shares		178,000
Tax withholding on ESPP purchases and vesting of RSUs	(4,175)	$ (1)	(4,174)
Tax withholding on ESPP purchases and vesting of RSUs, Shares		(109,000)
Vesting of RSUs		$ 3	(3)
Vesting of RSUs, Shares		326,000
Ending balance at Dec. 31, 2020	345,919	$ 772	393,911	(59,683)	10,919
Ending balance, Shares at Dec. 31, 2020		64,347,000
Beginning balance at Sep. 30, 2020	294,251	$ 766	368,813	(70,472)	(4,856)
Beginning balance, Shares at Sep. 30, 2020		63,843,000
Net income	10,789			10,789
Foreign currency translation adjustment	15,775				15,775
Issuance of ordinary shares upon exercise of share options	8,817	$ 5	8,812
Issuance of ordinary shares upon exercise of share options, Shares		378,000
Share-based compensation	13,833		13,833
ESPP purchases	3,321	$ 1	3,320
ESPP purchases, Shares		91,000
Tax withholding on ESPP purchases and vesting of RSUs	(867)		(867)
Tax withholding on ESPP purchases and vesting of RSUs, Shares		(17,000)
Vesting of RSUs, Shares		52,000
Ending balance at Dec. 31, 2020	345,919	$ 772	393,911	(59,683)	10,919
Ending balance, Shares at Dec. 31, 2020		64,347,000
Beginning balance at Mar. 31, 2021	$ 360,869	$ 775	408,249	(53,915)	5,760
Beginning balance, Shares at Mar. 31, 2021	64,562,222	64,562,000
Net income	$ 41,473			41,473
Foreign currency translation adjustment	5,363				5,363
Issuance of ordinary shares upon exercise of share options	$ 56,707	$ 21	56,686
Issuance of ordinary shares upon exercise of share options, Shares	1,750,407	1,750,000
Share-based compensation	$ 47,334		47,334
ESPP purchases	6,425	$ 1	6,424
ESPP purchases, Shares		142,000
Tax withholding on ESPP purchases and vesting of RSUs	(10,287)	$ (2)	(10,285)
Tax withholding on ESPP purchases and vesting of RSUs, Shares		(220,000)
Vesting of RSUs		$ 8	(8)
Vesting of RSUs, Shares		673,000
Ending balance at Dec. 31, 2021	$ 507,884	$ 803	508,400	(12,442)	11,123
Ending balance, Shares at Dec. 31, 2021	66,907,431	66,907,000
Beginning balance at Sep. 30, 2021	$ 459,458	$ 796	476,805	(26,260)	8,117
Beginning balance, Shares at Sep. 30, 2021		66,326,000
Net income	13,818			13,818
Foreign currency translation adjustment	3,006				3,006
Issuance of ordinary shares upon exercise of share options	15,989	$ 6	15,983
Issuance of ordinary shares upon exercise of share options, Shares		456,000
Share-based compensation	14,618		14,618
ESPP purchases	3,051		3,051
ESPP purchases, Shares		67,000
Tax withholding on ESPP purchases and vesting of RSUs	(2,056)		(2,056)
Tax withholding on ESPP purchases and vesting of RSUs, Shares		(28,000)
Vesting of RSUs		$ 1	(1)
Vesting of RSUs, Shares		86,000
Ending balance at Dec. 31, 2021	$ 507,884	$ 803	$ 508,400	$ (12,442)	$ 11,123
Ending balance, Shares at Dec. 31, 2021	66,907,431	66,907,000

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net income	$ 41,473	$ 23,977
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	29,838	28,297
Share-based compensation expense	47,365	41,064
Amortization of deferred contract costs	13,106	9,471
Amortization of debt issuance costs	331	344
Amortization of operating lease right-of-use assets	24,926	22,328
Deferred income tax expense (benefit)	602	(190)
Other non-cash items	(3)
Unrealized currency losses (gains) on foreign denominated transactions	1,233	(4,540)
Changes in assets and liabilities:
Accounts receivable	(7,180)	6,224
Prepaid expenses and other current assets	(946)	(1,700)
Deferred contract costs	(20,043)	(19,521)
Other assets	1,163	250
Accounts payable	799	(3,630)
Deferred revenue	16,442	2,537
Operating lease liabilities	(27,495)	(25,024)
Accrued expenses and other liabilities	8,549	15,439
Net cash provided by operating activities	130,160	95,326
Investing activities
Purchases of property, equipment and capitalized software	(29,401)	(30,931)
Purchases of strategic investments	(1,500)
Payments for acquisitions, net of cash acquired		(17,044)
Net cash used in investing activities	(30,901)	(47,975)
Financing activities
Proceeds from issuance of ordinary shares	63,097	31,113
Withholding taxes related to net share settlement of ESPP purchases and vesting of RSUs	(10,287)	(4,175)
Payments on debt including revolving credit facilities	(24,375)	(5,000)
Payments on finance lease obligations	(610)	(789)
Proceeds from long-term debt including revolving credit facilities		17,500
Net cash provided by financing activities	27,825	38,649
Effect of foreign exchange rates on cash	(3,860)	10,939
Net increase in cash and cash equivalents	123,224	96,939
Cash and cash equivalents at beginning of period	292,949	173,958
Cash and cash equivalents at end of period	416,173	270,897
Supplemental disclosure of cash flow information
Cash paid during the period for interest	1,222	2,163
Cash paid during the period for income taxes	1,878	1,228
Supplemental disclosure of non-cash investing and financing activities
Unpaid purchases of property, equipment and capitalized software	4,441	11,739
Operating lease right-of-use assets exchanged for lease obligations	12,289	30,216
Amounts due from seller for acquisitions		$ 74
Proceeds receivable from issuance of ordinary shares	35
Property and equipment acquired under finance lease	$ 716

Summary of Business and Signifi

Summary of Business and Significant Accounting Policies	6 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Business and Significant Accounting Policies	1. Summary of Business and Significant Accounting Policies Description of Business Mimecast Limited (Mimecast or the Company) is a public limited company organized under the laws of the Bailiwick of Jersey on July 28, 2015 and is headquartered in London, England. The principal activity of the Company is the provision of cloud security and risk management services for email and corporate information. The Company’s Email Security 3.0 and Cyber Resilience Extension offerings are designed to protect customers from today’s rapidly changing security environment. The Email Security 3.0 strategy addresses threats in three distinct zones: at the email perimeter (Zone 1); inside the network and the organization (Zone 2); and beyond the perimeter (Zone 3). The Company’s Cyber Resilience Extensions expand resilience to other critical elements of an organization’s digital infrastructure. The Company’s primary offerings include: email security; email continuity and sync & recover; email archiving; awareness training; web security; DMARC analyzer; CyberGraph; brand exploit protection; and threat intelligence and our API ecosystem . 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, security risks, management of international activities, protection of proprietary rights, patent litigation, and dependence on key individuals. Pending Transaction On December 7, 2021, the Company entered into a Transaction Agreement (Transaction Agreement) with Magnesium Bidco Limited, a private limited company incorporated in England & Wales (Buyer). Buyer is an affiliate of Permira Advisors LLC. The Transaction Agreement provides for the implementation of a Bailiwick of Jersey scheme of arrangement (Scheme of Arrangement) pursuant to which Buyer will acquire all of the Company’s shares (subject to certain exceptions) then outstanding as of the time that an act of the Royal Court of Jersey sanctioning the Scheme of Arrangement has been delivered to the Registrar of Companies in Jersey for registration (the “Effective Time”) and Company shareholders will be entitled, in accordance with the terms of the Scheme of Arrangement, to receive an amount in cash, without interest, equal to $ 80.00 per Company ordinary share that is outstanding immediately prior to the Effective Time. The completion of the transactions contemplated by the Transaction Agreement (Transaction) is subject to certain closing conditions, including approval by Company shareholders, receipt of regulatory approvals and such other conditions to completion as set forth in the Transaction Agreement. The Transaction is expected to close in the first half of 2022, subject to these closing conditions. Upon completion of the Transaction, the Company will become a privately held company and the ordinary shares of the Company will no longer be listed on any public market. Two special meetings of Company shareholders, the first to approve the Scheme of Arrangement for purposes of satisfying the requirements of the Companies (Jersey) Law 1991, as amended (the “Companies Law”), and the second to authorize the directors of the Company’s board of directors to take all actions as they consider necessary or appropriate for carrying the Scheme of Arrangement into effect and to amend the Company’s articles of association, are expected to be held in March 2022. Basis of Presentation The accompanying interim condensed consolidated financial statements are unaudited. These financial statements and notes should be read in conjunction with the audited consolidated financial statements for the year ended March 31, 2021 and related notes, together with management’s discussion and analysis of financial condition and results of operations, contained in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on May 27, 2021. The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP) for interim financial information, pursuant to the rules and regulations of the SEC. Accordingly, they do not include all of the financial information and footnotes required by GAAP for complete financial statements. In the opinion of management, the unaudited condensed consolidated financial statements and notes have been prepared on the same basis as the audited consolidated financial statements for the year ended March 31, 2021 contained in the Company’s Annual Report on Form 10-K and include all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of the Company’s financial position as of December 31, 2021, and for the three and nine months ended December 31, 2021 and 2020. These interim periods are not necessarily indicative of the results to be expected for any other interim period or the full year. The Company reclassified certain amounts within its condensed consolidated statement of cash flows to conform to current period presentation. The reclassifications include $ 0.7 million from other assets and $ 0.5 million from accrued expenses and other liabilities to deferred income tax expense (benefit) for the nine months ended December 31, 2020 . These reclassifications had no impact on the Company’s previously reported results of operations or balance sheets. Principles of Consolidation The condensed 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 condensed consolidated financial statements and the reported amounts of income and expenses during the reporting period. Significant estimates relied upon in preparing these condensed consolidated financial statements include revenue recognition, variable consideration, valuation at fair value of assets acquired or sold, including intangible assets, goodwill, tangible assets, and liabilities assumed, amortization periods, expected future cash flows used to evaluate the recoverability of long-lived assets, contingent liabilities, determination of incremental borrowing rates, 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. Due to the global COVID-19 pandemic, there has been uncertainty and disruption in the global economy and financial markets. The Company is not aware of any specific event or circumstance that would require an update to its estimates or judgments or a revision of the carrying value of its assets or liabilities as of December 31, 2021 . 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. Comprehensive Income Comprehensive income 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 income consists of net income and other comprehensive income, which includes certain changes in equity that are excluded from net income. As of December 31, 2021 and March 31, 2021 , accumulated other comprehensive income is presented separately on the condensed consolidated balance sheets and consists of cumulative foreign currency translation adjustments. Accounting Policies The accompanying condensed consolidated financial statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the condensed consolidated financial statements. As of December 31, 2021 , the Company’s significant accounting policies and estimates, which are detailed in the Company’s Annual Report on Form 10-K, have not changed.

Revenue and Deferred Revenue

Revenue and Deferred Revenue	9 Months Ended
	Dec. 31, 2021
Revenue From Contract With Customer [Abstract]
Revenue and Deferred Revenue	2. Revenue and Deferred Revenue Revenue recognized during the three and nine months ended December 31, 2021 from amounts included in deferred revenue at the beginning of the respective periods was approximately $ 105.0 million and $ 212.7 million, respectively. Revenue recognized during the three and nine months ended December 31, 2020 from amounts included in deferred revenue at the beginning of the respective periods was approximately $ 87.0 million and $ 177.0 million, respectively. Revenue recognized during the three and nine months ended December 31, 2021 and 2020 from performance obligations satisfied or partially satisfied in previous periods was not material. Contracted revenue as of December 31, 2021 and March 31, 2021 that has not yet been recognized (contracted and not recognized) was $ 145.3 million and $ 117.5 million, respectively, 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 53 % of contracted and not recognized revenue to be recognized over the next year, 46 % in years two and three, with the remaining balance recognized thereafter.

Concentration of Credit Risk an

Concentration of Credit Risk and Off-Balance Sheet Risk	9 Months Ended
	Dec. 31, 2021
Risks And Uncertainties [Abstract]
Concentration of Credit Risk and Off-Balance Sheet Risk	3. 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 the Company to concentrations of credit risk, consist primarily of cash and cash equivalents, investments and accounts receivable. The Company maintains its cash, cash equivalents and investments 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 the Company’s large number of customers. The Company’s accounts receivable are derived from revenue earned from customers primarily located in the United States, the United Kingdom, and South Africa. The Company generally does not require its customers to provide collateral or other security to support accounts receivable. The Company maintains an allowance for its doubtful accounts receivable due to estimated credit losses. The Company estimates credit losses at the reporting date resulting from the inability of its customers to make required payments, including its historical experience of actual losses and the aging of such receivables. These receivables have been pooled by shared risk characteristics. Based on known information the Company may also establish specific allowances for customers in an adverse financial condition or adjust its expectations of changes in conditions that may impact the collectability of outstanding receivables. 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. The Company will continue to actively monitor the impact of the global COVID-19 pandemic on expected credit losses. As of December 31, 2021 and March 31, 2021 , no individual customer represented more than 10% of the Company’s accounts receivable. During the three and nine months ended December 31, 2021 and 2020 , no individual customer represented more than 10% of the Company’s revenue. The Company generally diversifies its investment portfolio by investing in multiple types of investment-grade securities and attempts to mitigate the risk of loss by using a third-party investment manager. As of December 31, 2021, the Company's only investments consisted of convertible debt investments in privately held companies. As of March 31, 2021 , the Company did no t hold any investments.

Cash, Cash Equivalents and Inve

Cash, Cash Equivalents and Investments	9 Months Ended
	Dec. 31, 2021
Cash And Cash Equivalents [Abstract]
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 in the condensed consolidated statements of operations. As of December 31, 2021 and March 31, 2021 , cash and cash equivalents of $ 416.2 million and $ 292.9 million, respectively, were carried at amortized cost, which approximates their market value. Strategic investments consist of convertible debt investments in privately held companies. The Company has classified these convertible debt investments as of December 31, 2021, as available-for-sale pursuant to Accounting Standard Codification (ASC) 320, Investments - Debt Securities . Due to the conversion option and other embedded features, the Company has elected to record the convertible debt investments in their entirety at fair value with any changes in fair value recognized in "Foreign exchange (expense) income and other, net" on the condensed consolidated statements of operations. As of December 31, 2021 , the Company holds convertible debt investments that are due within two years with an amortized cost and a fair value of $ 1.5 million. These investments are included within other assets on the condensed consolidated balance sheets. During the three months ended December 31, 2021, the Company recognized immaterial unrealized gains related to changes in the fair value of the convertible debt investments. As of March 31, 2021 , the Company did no t hold any strategic investments.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	5. Fair Value of Financial Instruments 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 carrying amount of the Company’s long-term debt arrangements approximates its fair values due to the interest rates the Company believes it could obtain for arrangements with similar terms. The Company's convertible debt investments are classified as available-for-sale and reported at fair value in accordance with the market approach primarily utilizing unobservable inputs. The carrying amount of the remainder of the Company’s financial instruments approximated their fair values as of December 31, 2021 and March 31, 2021, due to the short-term nature of those instruments. 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 the Company has 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 December 31, 2021, the only assets or liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) are the Company's convertible debt investments. As of March 31, 2021 , the Company did no t have any assets or liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3). 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 elected the fair value option for the convertible debt investments transacted during the three months ended December 31, 2021. Other than the convertible debt investments, 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 three and nine months ended December 31, 2021 and the year ended March 31, 2021. The following table summarizes financial assets measured and recorded at fair value on a recurring basis in the accompanying condensed consolidated balance sheets as of December 31, 2021 and March 31, 2021, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: December 31, 2021 Quoted Prices in Significant Other Observable Inputs (Level 2 Inputs) Significant Unobservable Inputs (Level 3 Inputs) Total Assets: Money market funds $ 12,519 $ — $ — $ 12,519 Convertible debt investments — — 1,515 1,515 Total assets $ 12,519 $ — $ 1,515 $ 14,034 March 31, 2021 Quoted Prices in Significant Significant Unobservable Inputs (Level 3 Inputs) Total Assets: Money market funds $ 15,366 $ — $ — $ 15,366

Leases

Leases	9 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Leases	6. Leases The Company has operating leases for data centers and facilities and finance leases for certain equipment. The leases have remaining lease terms of less than one year to 7 years, some of which include options to extend the leases for up to 10 years. The Company recognizes lease expense for operating leases on a straight-line basis over the lease term. Variable costs, which are based on actual usage, are not included in the measurement of right-of-use assets (ROUA) and lease liabilities but are expensed when the event determining the amount of variable consideration to be paid occurs. Amortization expense of the ROUA for finance leases is recognized on a straight-line basis over the lease term and interest expense for finance leases is recognized based on the effective interest method using an incremental borrowing rate. The components of lease expense were as follows: Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Short-term lease cost $ 9 $ 40 $ 51 $ 128 Variable lease cost 1,353 1,536 4,403 5,094 Operating lease cost 9,681 9,390 29,079 26,712 Finance lease cost: Amortization of lease assets 70 250 372 750 Interest on lease liabilities 1 9 5 37 Total finance lease cost $ 71 $ 259 $ 377 $ 787 Supplemental cash flow information related to leases was as follows: Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash outflows from operating leases $ 10,335 $ 11,514 $ 32,125 $ 29,638 Operating cash outflows from finance leases $ 2 $ 5 $ 5 $ 37 Financing cash outflows from finance leases $ 263 $ 178 $ 610 $ 789 Weighted-average remaining lease term and discount rate: As of December 31, As of March 31, 2021 2021 Weighted-average remaining lease term (in years) Operating leases 5.35 5.76 Finance leases 0.66 0.35 Weighted-average discount rate Operating leases 4.42 % 4.58 % Finance leases 0.86 % 4.83 % Maturities of lease liabilities as of December 31, 2021 were as follows: Year Ending March 31, Operating Leases Finance Leases Remainder of 2022 $ 9,014 $ 123 2023 33,796 307 2024 25,576 — 2025 23,657 — 2026 19,237 — Thereafter 33,229 — Total lease payments 144,509 430 Less: imputed interest ( 15,837 ) ( 1 ) Total lease liabilities $ 128,672 $ 429 As of December 31, 2021 , the Company had no additional operating or finance leases that have not yet commenced.

Internal-use Software Costs

Internal-use Software Costs	9 Months Ended
	Dec. 31, 2021
Research And Development [Abstract]
Internal-use Software Costs	7. 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 three and nine months ended December 31, 2021 and 2020 , 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 condensed consolidated statements of operations as research and development expense. Implementation Costs on Cloud-computing Arrangements As of December 31, 2021 and March 31, 2021 , the net carrying value of capitalized implementation costs related to hosting arrangements that were incurred during the application development stage were $ 2.1 million and $ 2.9 million, respectively. These capitalized implementation costs will be amortized over the expected term of the arrangement and are amortized in the same line item in the condensed consolidated statements of operations as the expense for fees for the associated hosting arrangement.

Net Income Per Ordinary Share

Net Income Per Ordinary Share	9 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Income Per Ordinary Share	8. Net Income Per Ordinary Share The Company calculates basic and diluted net income per ordinary share by dividing net income by the weighted-average number of ordinary shares outstanding during the period. The following table presents the calculation of basic and diluted net income per share for the periods presented (in thousands, except per share data): Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Numerator: Net income $ 13,818 $ 10,789 $ 41,473 $ 23,977 Denominator: Weighted-average number of ordinary shares used in 66,575 63,987 65,921 63,509 Dilutive effect of share equivalents resulting from 3,558 2,036 2,846 1,910 Weighted-average number of ordinary shares used in 70,133 66,023 68,767 65,419 Net income per share applicable to ordinary Basic $ 0.21 $ 0.17 $ 0.63 $ 0.38 Diluted $ 0.20 $ 0.16 $ 0.60 $ 0.37 The following potentially dilutive ordinary share equivalents have been excluded from the calculation of diluted weighted-average shares outstanding as their effect would have been anti-dilutive for the periods presented (in thousands): Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Share options outstanding — 2,373 346 3,276 Unvested RSUs 67 101 426 402 ESPP shares — 82 — 166

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	9. Share-Based Compensation For the three and nine months ended December 31, 2021 and 2020 , all grants of share-based awards have been made under the Mimecast Limited 2015 Share Option and Incentive Plan (the 2015 Plan) and the 2015 Employee Share Purchase Plan (the ESPP). Additionally, the Company has two pre-IPO share-based compensation plans including the Mimecast Limited 2010 EMI Share Option Scheme (the 2010 Plan), and the Mimecast Limited Approved Share Option Plan (the Approved Plan) (the 2010 Plan and the Approved Plan, collectively, the Historical Plans). Subsequent to November 19, 2015, the IPO date, no further grants under the Historical Plans were permitted. The 2015 Plan allows the compensation committee of the board of directors to make equity-based incentive awards to the Company’s 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 1st by 5 % of the outstanding number of ordinary shares on the immediately preceding December 31 or such lesser number of shares as determined by the board of directors. 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 and RSU releases 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 each six-month offering period, which starts on the first business day in January and July each year. 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 Options The fair value of each share option issued under the 2015 Plan was estimated using the Black-Scholes option-pricing model that used the following weighted-average assumptions: Nine months ended December 31, 2021 2020 Expected term (in years) 6.1 6.1 Risk-free interest rate 1.3 % 0.5 % Expected volatility 46.6 % 44.6 % Expected dividend yield — % — % Grant date fair value per ordinary share $ 43.27 $ 35.17 The weighted-average per share fair value of options granted to employees during the nine months ended December 31, 2021 and 2020 was $ 19.84 and $ 15.07 , respectively. As of December 31, 2021 , the number of options and awards available for future grant under the 2015 Plan was 9,660,747 . Share option activity under the 2015 Plan and the Historical Plans for the nine months ended December 31, 2021 was as follows: Number of Weighted Average Weighted Average Aggregate Outstanding as of March 31, 2021 5,322,599 $ 34.13 6.81 $ 43,683 Options granted 842,928 $ 43.27 Options exercised ( 1,750,407 ) $ 32.40 Options forfeited and cancelled ( 481,556 ) $ 39.93 Outstanding as of December 31, 2021 3,933,564 $ 36.15 7.07 $ 170,792 Exercisable as of December 31, 2021 2,020,639 $ 30.62 5.92 $ 98,908 For the nine months ended December 31, 2021 and 2020 , the total intrinsic value of options exercised was $ 50.5 million and $ 28.8 million, respectively. For the nine months ended December 31, 2021 and 2020 , total cash proceeds from option exercises was $ 56.7 million and $ 24.7 million, respectively. As of December 31, 2021 , there was approximately $ 29.7 million of unrecognized share-based compensation related to unvested share options, which is expected to be recognized over a weighted-average period of 2.37 years. 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 nine months ended December 31, 2021 was as follows: Number of Weighted Average Intrinsic Unvested RSUs as of March 31, 2021 2,630,359 $ 38.62 $ 105,767 RSUs granted 2,039,568 $ 45.63 RSUs vested ( 672,988 ) $ 38.63 RSUs forfeited ( 646,902 ) $ 39.36 Unvested RSUs as of December 31, 2021 3,350,037 $ 42.74 $ 266,562 As of December 31, 2021 , there was approximately $ 115.3 million of unrecognized share-based compensation expense related to unvested RSUs, which is expected to be recognized over a weighted-average period of 2.92 years. ESPP In the three months ended December 31, 2021 and 2020 , the Company recognized $ 0.4 million and $ 0.6 million of share-based compensation expense under the ESPP, respectively. In the nine months ended December 31, 2021 and 2020 , the Company recognized share-based compensation expense under the ESPP of $ 1.4 million and $ 1.8 million respectively. In the nine months ended December 31, 2021 and 2020 total cash proceeds from shares purchased under the ESPP were $ 6.4 million and $ 6.4 million, respectively. As of December 31, 2021 , there were 0.4 million shares of the Company's ordinary shares available for future issuance under the ESPP. Under the terms of the Transaction Agreement, the Company has suspended the ESPP, effective as of January 1, 2022 . Share-based compensation expense recognized under the 2015 Plan, Historical Plans and ESPP in the accompanying condensed consolidated statements of operations was as follows: Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Cost of revenue $ 1,350 $ 1,247 $ 4,318 $ 3,535 Research and development 3,598 3,791 13,982 11,570 Sales and marketing 4,670 4,718 15,029 13,606 General and administrative 5,001 4,036 14,036 12,353 Total share-based compensation expense $ 14,619 $ 13,792 $ 47,365 $ 41,064

Acquisitions

Acquisitions	9 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Acquisitions	10. Acquisitions The following acquisition has been accounted for as a business combination in accordance with ASC 805, Business Combinations . The Company has recorded the assets acquired and liabilities assumed at their respective fair values as of the acquisition dates. Fiscal 2021 Acquisition eTorch Inc. On July 29, 2020 , the Company acquired eTorch Inc. (MessageControl), a company incorporated under the laws of the State of Delaware, for cash consideration of approximately $ 17.0 million, net of cash acquired of $ 0.4 million. MessageControl is a messaging security provider with solutions designed to help stop social engineering and human identity attacks with the use of machine learning technology. The purchase price allocation primarily consisted of $ 3.8 million of identifiable intangible assets and approximately $ 14.1 million of goodwill that is not deductible for tax purposes. The identifiable intangible assets primarily include developed technology of $ 3.5 million, customer relationships of $ 0.2 million, and patent licenses of $ 0.1 million, with estimated useful lives of 9.7 years, 6.7 years, and 5.0 years respectively. The goodwill reflects the value of the synergies the Company expects to realize and the assembled workforce. The Company has not presented pro forma results of operations for the MessageControl acquisition because it is not material to the Company's condensed consolidated results of operations, financial position, or cash flows.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Dec. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	11. Goodwill and Intangible Assets The following is a rollforward of the Company’s goodwill balance: Goodwill Balance as of March 31, 2021 $ 173,952 Effect of foreign exchange rates 6,648 Balance as of December 31, 2021 $ 180,600 Purchased intangible assets consisted of the following: Weighted- Average December 31, 2021 Remaining Gross Net Useful Life Carrying Accumulated Carrying (in years) Value Amortization Value Developed technology 6 $ 40,748 $ ( 12,851 ) $ 27,897 Customer relationships 4 996 ( 441 ) 555 Capitalized software and other (1) (2) 3 28,951 ( 16,459 ) 12,492 $ 70,695 $ ( 29,751 ) $ 40,944 Weighted- Average March 31, 2021 Remaining Gross Net Useful Life Carrying Accumulated Carrying (in years) Value Amortization Value Developed technology 7 $ 39,180 $ ( 9,114 ) $ 30,066 Customer relationships 4 984 ( 318 ) 666 Capitalized software and other (1) (2) 3 25,161 ( 12,700 ) 12,461 $ 65,325 $ ( 22,132 ) $ 43,193 (1) As of December 31, 2021 and March 31, 2021 , the net carrying value of capitalized software and other included $ 2.7 million and $ 2.1 million, respectively, of costs capitalized related to video production costs. (2) As of December 31, 2021 and March 31, 2021 , the net carrying value of capitalized software and other included $ 0.3 million and $ 0.3 million of costs capitalized related to IP addresses. For the three months ended December 31, 2021 and 2020 , the Company recorded amortization expense of $ 2.6 million and $ 2.5 million, respectively. For the nine months ended December 31, 2021 and 2020 , the Company recorded amortization expense of $ 7.5 million and $ 7.1 million, respectively. Amortization relating to developed technology and capitalized software was recorded within cost of revenue and amortization of customer relationships was recorded within sales and marketing expenses. Future estimated amortization expense of intangible assets as of December 31, 2021, is as follows: Purchased Capitalized Remainder of 2022 $ 1,164 $ 1,497 2023 4,655 4,752 2024 4,596 2,814 2025 4,519 1,853 2026 4,442 1,084 Thereafter 9,076 492 Total $ 28,452 $ 12,492

Debt

Debt	9 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Debt	12. Debt In July 2018, the Company entered into a credit agreement (the Credit Agreement) that 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). In June 2020, the Credit Agreement was amended to permit the Company to issue letters of credit in certain additional foreign currencies beyond the U.S. dollar and the British pound (as amended, the Credit Agreement, the Term Loan and the Revolving Facility are referred to herein as the Credit Facility). The term of the Credit Facility is five years , maturing on July 23, 2023 . As of December 31, 2021 and March 31, 2021 , the effective interest rate under the Credit Facility was LIBOR plus 1.375 %. The Credit Facility requires the Company to maintain compliance with certain debt covenants, all of which the Company was in compliance with as of December 31, 2021. As of December 31, 2021 and March 31, 2021 , the Company had $ 80.0 million and $ 86.9 million, respectively, outstanding on the Term Loan. As of March 31, 2021 , the Company had $ 17.5 million outstanding under the Revolving Facility. In the three months ended September 30, 2021 the Company repaid the $ 17.5 million outstanding borrowings under the Revolving Facility in full. As of December 31, 2021 and March 31, 2021 , total availability under the Revolving Facility was reduced by outstanding letters of credit of $ 2.1 million and $ 2.2 million, respectively. As of December 31, 2021 and March 31, 2021 , total availability under the Revolving Facility was $ 47.9 million and $ 30.3 million, respectively. Future minimum principal payment obligations under the Term Loan and Revolving Facility are as follows: Fiscal Year Ending March 31, Debt Remainder of 2022 $ 2,500 2023 10,000 2024 67,500 Total minimum debt payments 80,000 Less: Debt issuance costs ( 395 ) Less: Current portion of long-term debt ( 9,738 ) Long-term debt $ 69,867 As of December 31, 2021 and March 31, 2021 , the balance of debt issuance costs recorded as a reduction of debt was $ 0.4 million and $ 0.6 million, respectively. As of December 31, 2021 and March 31, 2021 , the balance of debt issuance costs recorded in other assets was $ 0.2 million and $ 0.3 million, respectively. For the three months ended December 31, 2021 and 2020 , total interest expense under the Credit Facility was $ 0.4 million and $ 0.5 million, respectively. For the nine months ended December 31, 2021 and 2020 , total interest expense under the Credit Facility was $ 1.2 million and $ 1.9 million, respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. Commitments and Contingencies Litigation On September 10, 2019, ZapFraud, Inc. (ZapFraud), filed a complaint in the U.S. District Court for the District of Delaware against the Company’s wholly owned subsidiaries, Mimecast North America, Inc., Mimecast Services Limited and Mimecast UK Limited. The complaint alleges that certain elements of the Company’s email security technology infringe a patent held by ZapFraud. ZapFraud seeks an award for damages in an unspecified amount, attorney’s fees and injunctive relief. On November 22, 2019, the Company filed a Motion to Dismiss for Failure to State a Claim. On April 24, 2020, ZapFraud amended its complaint by alleging that the Company’s email security technology infringes an additional patent that was recently issued to ZapFraud. On May 22, 2020, the Company filed a revised Motion to Dismiss for Failure to State a Claim that responds to ZapFraud’s amended complaint. On September 18, 2020, the court held a hearing on the motion and on November 20, 2020 the magistrate judge issued a recommendation that the court grant the Company’s motion. On December 11, 2020, ZapFraud filed objections to the magistrate judge’s recommendation and the Company responded to those objections on January 4, 2021. On March 25, 2021, the court adopted the recommendation of the magistrate judge, and granted the Company’s motion to dismiss. On September 22, 2021, the decision of the district court to adopt the magistrate judge’s recommendation became final and non-appealable. On January 14, 2022, in connection with the Transaction, a purported individual shareholder of Mimecast filed a complaint in the United States District Court for the Southern District of New York, captioned O’Dell v. Mimecast Limited, et al. , No. 1:22-cv-00367, naming as defendants the Company and each member of the Company’s Board of Directors as of the date of the Transaction Agreement (O’Dell). Between January 21, 2022 and January 25, 2022, three additional cases were filed by purported individual shareholders of Mimecast in the same court, captioned Whitfield v. Mimecast Limited, et al. , 1:22-cv-00579 (Whitfield), Smith v. Mimecast Limited, et al. , No.1:22-cv-00630 (Smith), and Hutchinson v. Mimecast Limited, et al. , No. 1:22-cv-00665 (Hutchinson), and on January 23, 2022, one additional case was filed by a purported individual shareholder of Mimecast in the United States District Court for the Eastern District of New York, captioned Mendoza v. Mimecast Limited, et al. , No. 1:22-cv-00384 (Mendoza). The O’Dell, Whitfield, Smith, Hutchinson, and Mendoza cases, and any similar subsequently filed cases involving the Company, the Company’s Board of Directors or any committee thereof and/or any of the Company’s directors or officers relating directly or indirectly to the Transaction Agreement, the Transaction or any related transaction, are referred to as the Transaction Litigations. The Transaction Litigations filed to date generally allege that the preliminary proxy statement filed by the Company with the Securities and Exchange Commission (SEC) on January 13, 2022 in connection with the Transaction is materially incomplete and misleading by allegedly failing to disclose purportedly material information relating to the sale process leading to the Transaction, Company financial projections, and the analyses performed by Citigroup Global Markets Inc., financial advisor to the Board of Directors and the special committee of the Board of Directors, in connection with the Transaction. The Transaction Litigations assert violations of Section 14(a) of the Securities Exchange Act of 1934 (the Exchange Act), Rule 14a-9 promulgated thereunder, and 17 C.F.R. § 244.100 against Mimecast and the members of the Company’s Board of Directors and violations of Section 20(a) of the Exchange Act against the Company’s Board of Directors. The Transaction Litigations seek, among other things: an injunction enjoining consummation of the Transaction, rescission of the Transaction Agreement, a declaration that the Company and the Company's Board of Directors violated Sections 14(a) and 20(a) of the Exchange Act and Rule 14a-9 promulgated thereunder, an order directing the Company's Board of Directors to comply with the Exchange Act, damages, costs of the action, including the plaintiff's attorneys' fees and experts' fees and expenses, and any other relief the court may deem just and proper. The Company cannot predict the outcome of each Transaction Litigation, nor can the Company predict the amount of time and expense that will be required to resolve each Transaction Litigation. The Company believes that the O’Dell, Smith, Hutchinson, Whitfield, and Mendoza cases are without merit and the Company and its directors intend to vigorously defend against each Transaction Litigation and any subsequently filed similar actions. It is possible that additional similar complaints could be filed in connection with the Transaction. If additional similar complaints are filed, absent new or significantly different allegations, Mimecast will not necessarily disclose such additional complaints or filings. 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, 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. Except as described above, the Company was not subject to any material legal proceedings during the nine months ended December 31, 2021 and 2020, and, to the best of its knowledge, except as described above, no material legal proceedings are currently pending or threatened. Indemnification In the ordinary course of business, the Company provides indemnifications of varying scope and terms to customers, business partners, vendors, lessors, directors, officers, employees, and other parties with respect to certain matters. Indemnification may include losses from intellectual property infringement claims made by third parties, the Company’s breach of certain agreements, and other liabilities relating to or arising from the Company’s acts or omissions. These indemnification provisions may survive termination of the underlying agreement and the maximum potential amount of future indemnification payments may not be subject to a cap. It is not possible to determine the maximum potential loss under these indemnification provisions due to the Company’s limited history of prior indemnification claims and the unique facts and circumstances involved in each particular indemnification. Based on historical experience and information known as of December 31, 2021 and March 31, 2021, the Company has not incurred any costs for the above 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. Security Incident In January 2021, the Company became aware of a security incident later determined to be conducted by the same sophisticated threat actor responsible for the SolarWinds supply chain attack. The Company immediately launched an internal forensic investigation. The investigation was supported by leading third-party forensics and cyber incident response experts at Mandiant, a division of FireEye, Inc., and in coordination with law enforcement to aid their investigation into this threat actor. During the investigation, the Company learned that the threat actor used the SolarWinds supply-chain compromise to gain access to part of its production grid environment. Using this entry point, the threat actor accessed certain Mimecast-issued certificates and related customer server connection information. The threat actor also accessed a subset of email addresses and other contact information, as well as encrypted and/or hashed and salted credentials. In addition, the threat actor accessed and downloaded a limited number of the Company’s source code repositories, but the Company found no evidence of any modifications to its source code nor does it believe there was any impact on its products. As the investigation progressed, the Company issued a series of advisories to affected customers, including recommended precautionary steps to mitigate risk and, in some cases, to address regulatory requirements. The forensic investigation was completed in March 2021 and the Company has eliminated the threat actor’s access to its environment. The Company has taken a number of actions to prevent future access to its environment and will continue to monitor for threats and take precautionary steps as needed. The Company is subject to risk and significant uncertainties as a result of this security incident, including those described in Part II, Item 1A, “Risk Factors” in this Quarterly Report on Form 10-Q. While the investigation is complete, there can be no assurance as to what the overall impact of these events will be. These types of events often have cascading impacts that unfold over time and may result in a loss of revenue, a diminution of the Company’s business prospects and incremental costs, including costs associated with litigation or investigations by regulatory authorities, any of which may adversely impact the Company’s financial results. The Company has incurred and expects to incur significant costs related to the security incident. For the year ended March 31, 2021, the Company recorded $ 0.8 million of pre-tax expenses related to the security incident, net of anticipated insurance recoveries. For the three and nine months ended December 31, 2021 , expenses related to the security incident were no t material. Expenses include costs of the forensic investigation, remediation costs, and legal and other professional services. It is also expected that the Company will continue to incur costs related to its response, remediation, and investigatory efforts relating to this security incident. While the Company has cyber insurance coverage, the amount of such insurance may be insufficient to compensate for any expenses or losses that may result from the security incident or the insurance carrier may refuse to reimburse the Company for certain costs under the terms of the policy. The full scope of the costs and related impacts of the security incident, including the availability of insurance to offset some of these costs, cannot be estimated at this time.

Restructuring

Restructuring	9 Months Ended
	Dec. 31, 2021
Restructuring And Related Activities [Abstract]
Restructuring	14. Restructuring Fiscal 2021 Restructuring On January 28, 2021, the Board of Directors of the Company approved a restructuring plan designed to align the Company’s resources with its strategy. The restructuring plan, which included a reduction of the Company’s workforce by approximately 4 %, permitted the Company to increase investment in strategic growth areas. During the year ended March 31, 2021, the Company recognized total pre-tax restructuring charges of $ 3.3 million, consisting of $ 3.7 million of severance and other one-time termination benefits, and other restructuring related costs, partially offset by $ 0.4 million of other adjustments. These charges were primarily cash-based and were recognized in the fourth quarter of fiscal 2021 in Restructuring in the consolidated statements of operations. Restructuring charges during the nine months ended December 31, 2021 were no t material. The actions associated with the restructuring plan are completed and the Company does not expect any material costs to be incurred in fiscal 2022. The following is a rollforward of the Company’s restructuring liability balance: Severance and Balance as of March 31, 2021 $ 398 Cash payments ( 398 ) Balance as of December 31, 2021 $ —

Segment and Geographic Informat

Segment and Geographic Information	9 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Segment and Geographic Information	15. Segment and Geographic Information 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: Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 United States $ 78,128 $ 65,942 $ 223,564 $ 189,864 United Kingdom 42,154 36,977 124,270 105,464 South Africa 15,017 13,732 45,676 37,419 Other 16,300 12,985 47,871 34,758 Total $ 151,599 $ 129,636 $ 441,381 $ 367,505 Property and equipment, net, by geographic location consists of the following: As of December 31, As of March 31, 2021 2021 United States $ 40,882 $ 40,129 United Kingdom 27,611 28,892 South Africa 6,650 7,942 Other 15,923 15,928 Total $ 91,066 $ 92,891

Income Taxes

Income Taxes	9 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	16. Income Taxes The provision for income taxes for the three months ended December 31, 2021 and 2020 was $ 1.7 million and $ 1.2 million, respectively, on income before income taxes of $ 15.5 million and $ 11.9 million, respectively. The provision for income taxes for the nine months ended December 31, 2021 and 2020 was $ 4.9 million and $ 2.4 million, respectively, on income before taxes of $ 46.4 million and $ 26.3 million, respectively. The provision for income taxes for the three and nine months ended December 31, 2021 was primarily attributable to the provision recorded on the earnings of the Company’s profitable entities, partially offset by discrete tax benefits of $ 1.3 million and $ 3.4 million related to excess tax benefits on share-based compensation realized by U.S. and U.K. employees. The provision for income taxes for the three and nine months ended December 31, 2020 was primarily attributable to the tax provision recorded on the earnings of the Company’s profitable entities, partially offset by the discrete tax benefit of $ 1.4 million and $ 4.5 million related to excess tax benefits on share-based compensation realized by U.S. and U.K employees. In addition, during the three and nine months ended December 31, 2020, the Company recorded a discrete tax benefit of $ 0.6 million for the release of a portion of the Company’s pre-existing U.S. valuation allowance as a result of the MessageControl business combination. In assessing the Company’s ability to realize its net deferred tax assets, the Company considered various factors including future reversals of existing taxable temporary differences, projected future taxable income, tax planning strategies and recent financial operations to determine whether it is more likely than not that some portion or all of its net deferred tax assets will not be realized. Based upon these factors, the Company has determined that the uncertainty regarding the realization of these assets is sufficient to warrant the need for a full valuation allowance against its net deferred tax assets as of December 31, 2021. It is possible that within the next 12 months, there may be sufficient positive evidence to release a portion or all of the valuation allowance. Release of the valuation allowance would result in a benefit to income tax expense for the period the release is recorded, which could have a material impact on net earnings. The timing and amount of the potential valuation allowance release are subject to significant management judgment. During the three and nine months ended December 31, 2021 , the Company did no t have a material change to the Company’s liabilities for uncertain tax positions. As of December 31, 2021, the Company did no t have any material uncertain tax positions that would impact the effective tax rate if recognized. Interest and penalty charges, if any, related to uncertain tax positions would be classified as income tax expense in the accompanying condensed consolidated statements of operations. As of December 31, 2021 and March 31, 2021 , accrued interest or penalties related to uncertain tax positions were immaterial.

Summary of Business and Signi_2

Summary of Business and Significant Accounting Policies (Policies)	9 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim condensed consolidated financial statements are unaudited. These financial statements and notes should be read in conjunction with the audited consolidated financial statements for the year ended March 31, 2021 and related notes, together with management’s discussion and analysis of financial condition and results of operations, contained in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on May 27, 2021. The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP) for interim financial information, pursuant to the rules and regulations of the SEC. Accordingly, they do not include all of the financial information and footnotes required by GAAP for complete financial statements. In the opinion of management, the unaudited condensed consolidated financial statements and notes have been prepared on the same basis as the audited consolidated financial statements for the year ended March 31, 2021 contained in the Company’s Annual Report on Form 10-K and include all adjustments, consisting of normal recurring adjustments, necessary for a fair presentation of the Company’s financial position as of December 31, 2021, and for the three and nine months ended December 31, 2021 and 2020. These interim periods are not necessarily indicative of the results to be expected for any other interim period or the full year. The Company reclassified certain amounts within its condensed consolidated statement of cash flows to conform to current period presentation. The reclassifications include $ 0.7 million from other assets and $ 0.5 million from accrued expenses and other liabilities to deferred income tax expense (benefit) for the nine months ended December 31, 2020 . These reclassifications had no impact on the Company’s previously reported results of operations or balance sheets.
Principles of Consolidation	Principles of Consolidation The condensed 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 condensed consolidated financial statements and the reported amounts of income and expenses during the reporting period. Significant estimates relied upon in preparing these condensed consolidated financial statements include revenue recognition, variable consideration, valuation at fair value of assets acquired or sold, including intangible assets, goodwill, tangible assets, and liabilities assumed, amortization periods, expected future cash flows used to evaluate the recoverability of long-lived assets, contingent liabilities, determination of incremental borrowing rates, 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. Due to the global COVID-19 pandemic, there has been uncertainty and disruption in the global economy and financial markets. The Company is not aware of any specific event or circumstance that would require an update to its estimates or judgments or a revision of the carrying value of its assets or liabilities as of December 31, 2021 . 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.
Comprehensive Income	Comprehensive Income Comprehensive income 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 income consists of net income and other comprehensive income, which includes certain changes in equity that are excluded from net income. As of December 31, 2021 and March 31, 2021 , accumulated other comprehensive income is presented separately on the condensed consolidated balance sheets and consists of cumulative foreign currency translation adjustments.
Revenue and Deferred Revenue	Revenue and Deferred Revenue Revenue recognized during the three and nine months ended December 31, 2021 from amounts included in deferred revenue at the beginning of the respective periods was approximately $ 105.0 million and $ 212.7 million, respectively. Revenue recognized during the three and nine months ended December 31, 2020 from amounts included in deferred revenue at the beginning of the respective periods was approximately $ 87.0 million and $ 177.0 million, respectively. Revenue recognized during the three and nine months ended December 31, 2021 and 2020 from performance obligations satisfied or partially satisfied in previous periods was not material. Contracted revenue as of December 31, 2021 and March 31, 2021 that has not yet been recognized (contracted and not recognized) was $ 145.3 million and $ 117.5 million, respectively, 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 53 % of contracted and not recognized revenue to be recognized over the next year, 46 % in years two and three, with the remaining balance recognized thereafter.
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 the Company to concentrations of credit risk, consist primarily of cash and cash equivalents, investments and accounts receivable. The Company maintains its cash, cash equivalents and investments 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 the Company’s large number of customers. The Company’s accounts receivable are derived from revenue earned from customers primarily located in the United States, the United Kingdom, and South Africa. The Company generally does not require its customers to provide collateral or other security to support accounts receivable. The Company maintains an allowance for its doubtful accounts receivable due to estimated credit losses. The Company estimates credit losses at the reporting date resulting from the inability of its customers to make required payments, including its historical experience of actual losses and the aging of such receivables. These receivables have been pooled by shared risk characteristics. Based on known information the Company may also establish specific allowances for customers in an adverse financial condition or adjust its expectations of changes in conditions that may impact the collectability of outstanding receivables. 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. The Company will continue to actively monitor the impact of the global COVID-19 pandemic on expected credit losses. As of December 31, 2021 and March 31, 2021 , no individual customer represented more than 10% of the Company’s accounts receivable. During the three and nine months ended December 31, 2021 and 2020 , no individual customer represented more than 10% of the Company’s revenue. The Company generally diversifies its investment portfolio by investing in multiple types of investment-grade securities and attempts to mitigate the risk of loss by using a third-party investment manager. As of December 31, 2021, the Company's only investments consisted of convertible debt investments in privately held companies. As of March 31, 2021 , the Company did no t hold any investments.
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 in the condensed consolidated statements of operations. As of December 31, 2021 and March 31, 2021 , cash and cash equivalents of $ 416.2 million and $ 292.9 million, respectively, were carried at amortized cost, which approximates their market value. Strategic investments consist of convertible debt investments in privately held companies. The Company has classified these convertible debt investments as of December 31, 2021, as available-for-sale pursuant to Accounting Standard Codification (ASC) 320, Investments - Debt Securities . Due to the conversion option and other embedded features, the Company has elected to record the convertible debt investments in their entirety at fair value with any changes in fair value recognized in "Foreign exchange (expense) income and other, net" on the condensed consolidated statements of operations. As of December 31, 2021 , the Company holds convertible debt investments that are due within two years with an amortized cost and a fair value of $ 1.5 million. These investments are included within other assets on the condensed consolidated balance sheets. During the three months ended December 31, 2021, the Company recognized immaterial unrealized gains related to changes in the fair value of the convertible debt investments. As of March 31, 2021 , the Company did no t hold any strategic investments.
Internal-use Software Costs	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 three and nine months ended December 31, 2021 and 2020 , 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 condensed consolidated statements of operations as research and development expense. Implementation Costs on Cloud-computing Arrangements As of December 31, 2021 and March 31, 2021 , the net carrying value of capitalized implementation costs related to hosting arrangements that were incurred during the application development stage were $ 2.1 million and $ 2.9 million, respectively. These capitalized implementation costs will be amortized over the expected term of the arrangement and are amortized in the same line item in the condensed consolidated statements of operations as the expense for fees for the associated hosting arrangement.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Dec. 31, 2021
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 condensed consolidated balance sheets as of December 31, 2021 and March 31, 2021, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value: December 31, 2021 Quoted Prices in Significant Other Observable Inputs (Level 2 Inputs) Significant Unobservable Inputs (Level 3 Inputs) Total Assets: Money market funds $ 12,519 $ — $ — $ 12,519 Convertible debt investments — — 1,515 1,515 Total assets $ 12,519 $ — $ 1,515 $ 14,034 March 31, 2021 Quoted Prices in Significant Significant Unobservable Inputs (Level 3 Inputs) Total Assets: Money market funds $ 15,366 $ — $ — $ 15,366

Leases (Tables)

Leases (Tables)	9 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Schedule of Components of Lease Expense	The components of lease expense were as follows: Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Short-term lease cost $ 9 $ 40 $ 51 $ 128 Variable lease cost 1,353 1,536 4,403 5,094 Operating lease cost 9,681 9,390 29,079 26,712 Finance lease cost: Amortization of lease assets 70 250 372 750 Interest on lease liabilities 1 9 5 37 Total finance lease cost $ 71 $ 259 $ 377 $ 787
Schedule of Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases was as follows: Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash outflows from operating leases $ 10,335 $ 11,514 $ 32,125 $ 29,638 Operating cash outflows from finance leases $ 2 $ 5 $ 5 $ 37 Financing cash outflows from finance leases $ 263 $ 178 $ 610 $ 789
Schedule of Weighted-average Remaining Lease Term and Discount Rate	Weighted-average remaining lease term and discount rate: As of December 31, As of March 31, 2021 2021 Weighted-average remaining lease term (in years) Operating leases 5.35 5.76 Finance leases 0.66 0.35 Weighted-average discount rate Operating leases 4.42 % 4.58 % Finance leases 0.86 % 4.83 %
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities as of December 31, 2021 were as follows: Year Ending March 31, Operating Leases Finance Leases Remainder of 2022 $ 9,014 $ 123 2023 33,796 307 2024 25,576 — 2025 23,657 — 2026 19,237 — Thereafter 33,229 — Total lease payments 144,509 430 Less: imputed interest ( 15,837 ) ( 1 ) Total lease liabilities $ 128,672 $ 429

Net Income Per Ordinary Share (

Net Income Per Ordinary Share (Tables)	9 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Schedule for Calculation of Basic and Diluted Net Income Per Share	The following table presents the calculation of basic and diluted net income per share for the periods presented (in thousands, except per share data): Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Numerator: Net income $ 13,818 $ 10,789 $ 41,473 $ 23,977 Denominator: Weighted-average number of ordinary shares used in 66,575 63,987 65,921 63,509 Dilutive effect of share equivalents resulting from 3,558 2,036 2,846 1,910 Weighted-average number of ordinary shares used in 70,133 66,023 68,767 65,419 Net income per share applicable to ordinary Basic $ 0.21 $ 0.17 $ 0.63 $ 0.38 Diluted $ 0.20 $ 0.16 $ 0.60 $ 0.37
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 as their effect would have been anti-dilutive for the periods presented (in thousands): Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Share options outstanding — 2,373 346 3,276 Unvested RSUs 67 101 426 402 ESPP shares — 82 — 166

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Weighted Average Assumption Utilized to Determine Fair Value of Option	The fair value of each share option issued under the 2015 Plan was estimated using the Black-Scholes option-pricing model that used the following weighted-average assumptions: Nine months ended December 31, 2021 2020 Expected term (in years) 6.1 6.1 Risk-free interest rate 1.3 % 0.5 % Expected volatility 46.6 % 44.6 % Expected dividend yield — % — % Grant date fair value per ordinary share $ 43.27 $ 35.17
Schedule of Share-Based Compensation, Stock Options, Activity	Share option activity under the 2015 Plan and the Historical Plans for the nine months ended December 31, 2021 was as follows: Number of Weighted Average Weighted Average Aggregate Outstanding as of March 31, 2021 5,322,599 $ 34.13 6.81 $ 43,683 Options granted 842,928 $ 43.27 Options exercised ( 1,750,407 ) $ 32.40 Options forfeited and cancelled ( 481,556 ) $ 39.93 Outstanding as of December 31, 2021 3,933,564 $ 36.15 7.07 $ 170,792 Exercisable as of December 31, 2021 2,020,639 $ 30.62 5.92 $ 98,908
Schedule of Share-Based Compensation, RSUs, Activity	RSU activity under the 2015 Plan for the nine months ended December 31, 2021 was as follows: Number of Weighted Average Intrinsic Unvested RSUs as of March 31, 2021 2,630,359 $ 38.62 $ 105,767 RSUs granted 2,039,568 $ 45.63 RSUs vested ( 672,988 ) $ 38.63 RSUs forfeited ( 646,902 ) $ 39.36 Unvested RSUs as of December 31, 2021 3,350,037 $ 42.74 $ 266,562
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 condensed consolidated statements of operations was as follows: Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 Cost of revenue $ 1,350 $ 1,247 $ 4,318 $ 3,535 Research and development 3,598 3,791 13,982 11,570 Sales and marketing 4,670 4,718 15,029 13,606 General and administrative 5,001 4,036 14,036 12,353 Total share-based compensation expense $ 14,619 $ 13,792 $ 47,365 $ 41,064

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Dec. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Goodwill Balance	The following is a rollforward of the Company’s goodwill balance: Goodwill Balance as of March 31, 2021 $ 173,952 Effect of foreign exchange rates 6,648 Balance as of December 31, 2021 $ 180,600
Schedule of Purchased Intangible Assets	Purchased intangible assets consisted of the following: Weighted- Average December 31, 2021 Remaining Gross Net Useful Life Carrying Accumulated Carrying (in years) Value Amortization Value Developed technology 6 $ 40,748 $ ( 12,851 ) $ 27,897 Customer relationships 4 996 ( 441 ) 555 Capitalized software and other (1) (2) 3 28,951 ( 16,459 ) 12,492 $ 70,695 $ ( 29,751 ) $ 40,944 Weighted- Average March 31, 2021 Remaining Gross Net Useful Life Carrying Accumulated Carrying (in years) Value Amortization Value Developed technology 7 $ 39,180 $ ( 9,114 ) $ 30,066 Customer relationships 4 984 ( 318 ) 666 Capitalized software and other (1) (2) 3 25,161 ( 12,700 ) 12,461 $ 65,325 $ ( 22,132 ) $ 43,193 (1) As of December 31, 2021 and March 31, 2021 , the net carrying value of capitalized software and other included $ 2.7 million and $ 2.1 million, respectively, of costs capitalized related to video production costs. (2) As of December 31, 2021 and March 31, 2021 , the net carrying value of capitalized software and other included $ 0.3 million and $ 0.3 million of costs capitalized related to IP addresses.
Schedule of Future Estimated Amortization Expense of Acquired Intangible Assets	Future estimated amortization expense of intangible assets as of December 31, 2021, is as follows: Purchased Capitalized Remainder of 2022 $ 1,164 $ 1,497 2023 4,655 4,752 2024 4,596 2,814 2025 4,519 1,853 2026 4,442 1,084 Thereafter 9,076 492 Total $ 28,452 $ 12,492

Debt (Tables)

Debt (Tables)	9 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of Future Minimum Principal Payment Obligations	Future minimum principal payment obligations under the Term Loan and Revolving Facility are as follows: Fiscal Year Ending March 31, Debt Remainder of 2022 $ 2,500 2023 10,000 2024 67,500 Total minimum debt payments 80,000 Less: Debt issuance costs ( 395 ) Less: Current portion of long-term debt ( 9,738 ) Long-term debt $ 69,867

Restructuring (Tables)

Restructuring (Tables)	9 Months Ended
	Dec. 31, 2021
Restructuring And Related Activities [Abstract]
Schedule of Restructuring Liability Balance	The following is a rollforward of the Company’s restructuring liability balance: Severance and Balance as of March 31, 2021 $ 398 Cash payments ( 398 ) Balance as of December 31, 2021 $ —

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	9 Months Ended
	Dec. 31, 2021
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: Three months ended December 31, Nine months ended December 31, 2021 2020 2021 2020 United States $ 78,128 $ 65,942 $ 223,564 $ 189,864 United Kingdom 42,154 36,977 124,270 105,464 South Africa 15,017 13,732 45,676 37,419 Other 16,300 12,985 47,871 34,758 Total $ 151,599 $ 129,636 $ 441,381 $ 367,505
Summary of Property and Equipment, Net by Geographic Location	Property and equipment, net, by geographic location consists of the following: As of December 31, As of March 31, 2021 2021 United States $ 40,882 $ 40,129 United Kingdom 27,611 28,892 South Africa 6,650 7,942 Other 15,923 15,928 Total $ 91,066 $ 92,891

Summary of Business and Signi_3

Summary of Business and Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Dec. 31, 2021	Dec. 07, 2021
Accounting Policies [Abstract]
Reclassified from other assets to deferred income tax expense (benefit)	$ 0.7
Cash entitled to receive for each ordinary share		$ 80
Reclassified from accrued expenses and other liabilities to deferred income tax expense (benefit)	$ 0.5

Revenue and Deferred Revenue -

Revenue and Deferred Revenue - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2021
Revenue From Contract With Customer [Abstract]
Revenue recognized included in deferred revenue	$ 105	$ 87	$ 212.7	$ 177
Contracted revenue not yet recognized	$ 145.3		$ 145.3		$ 117.5
Contracted revenue not yet recognized, expected timing of satisfaction, explanation			The Company expects 53% of contracted and not recognized revenue to be recognized over the next year, 46% in years two and three, with the remaining balance recognized thereafter.

Revenue and Deferred Revenue _2

Revenue and Deferred Revenue - Additional Information (Detail 1)	Dec. 31, 2021
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation, percentage	53.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2023-01-01
Disaggregation Of Revenue [Line Items]
Revenue, remaining performance obligation, percentage	46.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period	24 months

Concentration of Credit Risk _2

Concentration of Credit Risk and Off-Balance Sheet Risk - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Dec. 31, 2021Customer	Dec. 31, 2020Customer	Dec. 31, 2021Customer	Dec. 31, 2020Customer	Mar. 31, 2021USD ($)Customer
Risks And Uncertainties [Abstract]
Number of customers representing more than 10% of accounts receivable	0		0		0
Number of customers representing more than 10% of revenue	0	0	0	0
Investments | $					$ 0

Cash, Cash Equivalents and In_2

Cash, Cash Equivalents and Investments - Additional Information (Detail) - USD ($)	Dec. 31, 2021	Mar. 31, 2021
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 416,173,000	$ 292,949,000
Strategic Investments [Member]
Cash and Cash Equivalents [Line Items]
Convertible debt investments hold with amortized cost and fair value	$ 1,500,000	$ 0

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Additional Information (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)	Dec. 31, 2021	Mar. 31, 2021
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Assets measured at fair value on a recurring basis	$ 14,034,000
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	$ 1,515,000	$ 0
Liabilities measured at fair value on a recurring basis		$ 0

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Summary of Financial Assets Measured and Recorded at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)	Dec. 31, 2021	Mar. 31, 2021
Assets:
Total assets	$ 14,034,000
Money Market Funds [Member]
Assets:
Total assets	12,519,000	$ 15,366,000
Convertible debt investments
Assets:
Total assets	1,515,000
Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs) [Member]
Assets:
Total assets	12,519,000
Quoted Prices in Active Markets for Identical Assets (Level 1 Inputs) [Member] | Money Market Funds [Member]
Assets:
Total assets	12,519,000	15,366,000
Fair Value Inputs Level3 [Member]
Assets:
Total assets	1,515,000	$ 0
Fair Value Inputs Level3 [Member] | Convertible debt investments
Assets:
Total assets	$ 1,515,000

Leases - Additional Information

Leases - Additional Information (Detail)	9 Months Ended
	Dec. 31, 2021USD ($)
Lessee Lease Description [Line Items]
Operating and finance leases, existence of option to extend [true false]	true
Operating and finance leases, option to extend, description	some of which include options to extend the leases for up to 10 years.
Leases not yet commenced, description	no additional operating or finance leases that have not yet commenced.
Leases not yet commenced, value	$ 0
Minimum [Member]
Lessee Lease Description [Line Items]
Operating and finance leases, remaining lease term	1 year
Maximum [Member]
Lessee Lease Description [Line Items]
Operating and finance leases, remaining lease term	7 years
Operating and finance leases, renewal term	10 years

Leases - Schedule of Components

Leases - Schedule of Components of Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Short-term lease cost	$ 9	$ 40	$ 51	$ 128
Variable lease cost	1,353	1,536	4,403	5,094
Operating lease cost	9,681	9,390	29,079	26,712
Finance lease cost:
Amortization of lease assets	70	250	372	750
Interest on lease liabilities	1	9	5	37
Total finance lease cost	$ 71	$ 259	$ 377	$ 787

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash outflows from operating leases	$ 10,335	$ 11,514	$ 32,125	$ 29,638
Operating cash outflows from finance leases	2	5	5	37
Financing cash outflows from finance leases	$ 263	$ 178	$ 610	$ 789

Leases - Schedule of Weighted-a

Leases - Schedule of Weighted-average Remaining Lease Term and Discount Rate (Detail)	Dec. 31, 2021	Mar. 31, 2021
Leases [Abstract]
Operating leases, Weighted-average remaining lease term	5 years 4 months 6 days	5 years 9 months 3 days
Finance leases, Weighted-average remaining lease term	7 months 28 days	4 months 6 days
Operating leases, Weighted-average discount rate	4.42%	4.58%
Finance leases, Weighted-average discount rate	0.86%	4.83%

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Lease Liabilities (Detail) $ in Thousands	Dec. 31, 2021USD ($)
Operating Leases
Remainder of 2022	$ 9,014
2023	33,796
2024	25,576
2025	23,657
2026	19,237
Thereafter	33,229
Total lease payments	144,509
Less: imputed interest	(15,837)
Total lease liabilities	128,672
Finance Leases
Remainder of 2022	123
2023	307
Total lease payments	430
Less: imputed interest	(1)
Total lease liabilities	$ 429

Internal-use Software Costs - A

Internal-use Software Costs - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2021
Research And Development [Abstract]
Capitalized costs	$ 0	$ 0	$ 0	$ 0
Implementation costs capitalized			$ 2,100,000		$ 2,900,000

Net Income Per Ordinary Share -

Net Income Per Ordinary Share - Schedule for Calculation of Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net income	$ 13,818	$ 10,789	$ 41,473	$ 23,977
Weighted-average number of ordinary shares used in computing net income per share applicable to ordinary shareholders – basic	66,575	63,987	65,921	63,509
Dilutive effect of share equivalents resulting from share options, RSUs and ESPP shares	3,558	2,036	2,846	1,910
Weighted-average number of ordinary shares used in computing net income per share – diluted	70,133	66,023	68,767	65,419
Net income per share applicable to ordinary shareholders:
Basic	$ 0.21	$ 0.17	$ 0.63	$ 0.38
Diluted	$ 0.20	$ 0.16	$ 0.60	$ 0.37

Net Income Per Ordinary Share_2

Net Income Per Ordinary Share - Dilutive Ordinary Shares Excluded from Calculation of Diluted Weighted Average Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
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		2,373	346	3,276
Unvested Restricted Share Units [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	67	101	426	402
ESPP Shares [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		82		166

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands	3 Months Ended			9 Months Ended
	Dec. 31, 2021USD ($)CompensationPlanshares	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2021USD ($)InstallmentCompensationPlan$ / sharesshares	Dec. 31, 2020USD ($)$ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of share-based compensation plans | CompensationPlan	2			2
Weighted average per share fair value of options granted to employees | $ / shares				$ 19.84	$ 15.07
Total intrinsic value of options exercised				$ 50,500	$ 28,800
Proceeds from exercises of share-based awards				56,700	24,700
Share-based compensation expense recognized		$ 14,619	$ 13,792	47,365	41,064
Share Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense	$ 29,700			$ 29,700
Unrecognized share-based compensation expense, net of estimated forfeiture, period for recognition				2 years 4 months 13 days
Unvested Restricted Share Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense	$ 115,300			$ 115,300
Unrecognized share-based compensation expense, net of estimated forfeiture, period for recognition				2 years 11 months 1 day
Unvested Restricted Share Units [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 Restricted Share Units [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 Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options available for future grant | shares	9,660,747			9,660,747
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			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			1,100,000
Authorized payroll deductions percentage	10.00%			10.00%
Percentage of fair market value of shares to be considered as share price				85.00%
Number of options available for future grant | shares	400,000			400,000
Share based compensation, date of suspension of awards				Jan. 1, 2022
Share-based compensation expense recognized	$ 400		$ 600	$ 1,400	1,800
Cash proceeds from shares purchased in connection with ESPP				$ 6,400	$ 6,400
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 - Summ

Share-Based Compensation - Summary of Weighted-Average Assumption Utilized to Determine Fair Value of Option (Detail) - Share Options [Member] - $ / shares	9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
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
Risk-free interest rate	1.30%	0.50%
Expected volatility	46.60%	44.60%
Grant date fair value per ordinary share	$ 43.27	$ 35.17

Share-Based Compensation - Sche

Share-Based Compensation - Schedule of Share-Based Compensation, Stock Options, Activity (Detail) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares	Mar. 31, 2021USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Awards, Beginning balance | shares	5,322,599
Number of Awards, Options granted | shares	842,928
Number of Awards, Options exercised | shares	(1,750,407)
Number of Awards, Options forfeited and cancelled | shares	(481,556)
Number of Awards, Ending balance | shares	3,933,564	5,322,599
Number of Awards, Exercisable | shares	2,020,639
Weighted Average Exercise Price, Beginning balance | $ / shares	$ 34.13
Weighted Average Exercise Price, Options granted | $ / shares	43.27
Weighted Average Exercise Price, Options exercised | $ / shares	32.40
Weighted Average Exercise Price, Options forfeited and cancelled | $ / shares	39.93
Weighted Average Exercise Price, Ending balance | $ / shares	36.15	$ 34.13
Weighted Average Exercise Price Exercisable | $ / shares	$ 30.62
Weighted Average Remaining Contractual Term, Outstanding	7 years 25 days	6 years 9 months 21 days
Weighted Average Remaining Contractual Term, Exercisable	5 years 11 months 1 day
Aggregate Intrinsic Value, Outstanding | $	$ 170,792	$ 43,683
Aggregate Intrinsic Value, Exercisable | $	$ 98,908

Share-Based Compensation - Sc_2

Share-Based Compensation - Schedule of Share-Based Compensation, RSUs, Activity (Detail) $ / shares in Units, $ in Thousands	9 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Awards Unvested, RSUs Beginning balance | shares	2,630,359
Number of Awards, RSUs granted | shares	2,039,568
Number of Awards, RSUs vested | shares	(672,988)
Number of Awards, RSUs forfeited | shares	(646,902)
Number of Awards, Unvested RSUs, Ending balance | shares	3,350,037
Weighted Average Grant Date Fair Value, Unvested RSUs, Beginning balance | $ / shares	$ 38.62
Weighted Average Grant Date Fair Value, RSUs granted | $ / shares	45.63
Weighted Average Grant Date Fair Value, RSUs vested | $ / shares	38.63
Weighted Average Grant Date Fair Value, RSUs forfeited | $ / shares	39.36
Weighted Average Grant Date Fair Value, Unvested RSUs, Ending balance | $ / shares	$ 42.74
Intrinsic Value, Unvested RSUs, Beginning balance | $	$ 105,767
Intrinsic Value, Unvested RSUs, Ending Balance | $	$ 266,562

Share-Based Compensation - Shar

Share-Based Compensation - Share-Based Compensation Expense Recognized in Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	$ 14,619	$ 13,792	$ 47,365	$ 41,064
Cost of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	1,350	1,247	4,318	3,535
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	3,598	3,791	13,982	11,570
Sales and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	4,670	4,718	15,029	13,606
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total share-based compensation expense	$ 5,001	$ 4,036	$ 14,036	$ 12,353

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	Jul. 29, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2021
Business Acquisition [Line Items]
Net of cash acquired			$ 17,044
Goodwill		$ 180,600		$ 173,952
Developed Technology [Member]
Business Acquisition [Line Items]
Estimated Useful Life (in years)		6 years		7 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Estimated Useful Life (in years)		4 years		4 years
eTorch Inc. [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, amount	$ 3,800
Goodwill	14,100
eTorch Inc. [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, amount	$ 3,500
Estimated Useful Life (in years)	9 years 8 months 12 days
eTorch Inc. [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, amount	$ 200
Estimated Useful Life (in years)	6 years 8 months 12 days
eTorch Inc. [Member] | Patent Licenses [Member]
Business Acquisition [Line Items]
Estimated fair values of identifiable intangible assets, amount	$ 100
Estimated Useful Life (in years)	5 years
eTorch Inc. [Member] | Delaware [Member]
Business Acquisition [Line Items]
Business acquisition, effective date of acquisition	Jul. 29, 2020
Cash payment	$ 17,000
Net of cash acquired	$ 400

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Goodwill Balance (Detail) $ in Thousands	9 Months Ended
	Dec. 31, 2021USD ($)
Goodwill Roll Forward
Beginning Balance	$ 173,952
Effect of foreign exchange rates	6,648
Ending Balance	$ 180,600

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2021	Mar. 31, 2021
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross Carrying Value	$ 70,695	$ 65,325
Accumulated Amortization	(29,751)	(22,132)
Finite-Lived Intangible Assets, Net Carrying Value	$ 40,944	$ 43,193
Developed Technology [Member]
Finite Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Life (in years)	6 years	7 years
Finite-Lived Intangible Assets, Gross Carrying Value	$ 40,748	$ 39,180
Accumulated Amortization	(12,851)	(9,114)
Finite-Lived Intangible Assets, Net Carrying Value	$ 27,897	$ 30,066
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Weighted-Average Remaining Useful Life (in years)	4 years	4 years
Finite-Lived Intangible Assets, Gross Carrying Value	$ 996	$ 984
Accumulated Amortization	(441)	(318)
Finite-Lived Intangible Assets, Net Carrying Value	$ 555	$ 666
Capitalized Software and Other [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	$ 28,951	$ 25,161
Accumulated Amortization	(16,459)	(12,700)
Finite-Lived Intangible Assets, Net Carrying Value	$ 12,492	$ 12,461

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Schedule of Intangible Assets (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Mar. 31, 2021
Video Production Costs [Member]
Finite Lived Intangible Assets [Line Items]
Capitalized software and other cost	$ 2.7	$ 2.1
IP Addresses [Member]
Finite Lived Intangible Assets [Line Items]
Capitalized software and other cost	$ 0.3	$ 0.3

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense	$ 2.6	$ 2.5	$ 7.5	$ 7.1

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets - Schedule of Future Estimated Amortization Expense of Acquired Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net Carrying Value	$ 40,944	$ 43,193
Purchased Intangible Assets [Member]
Finite Lived Intangible Assets [Line Items]
Remainder of 2022	1,164
2023	4,655
2024	4,596
2025	4,519
2026	4,442
Thereafter	9,076
Finite-Lived Intangible Assets, Net Carrying Value	28,452
Capitalized Software [Member]
Finite Lived Intangible Assets [Line Items]
Remainder of 2022	1,497
2023	4,752
2024	2,814
2025	1,853
2026	1,084
Thereafter	492
Finite-Lived Intangible Assets, Net Carrying Value	$ 12,492

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)	Jul. 23, 2018	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2021
Debt Instrument [Line Items]
Repayment of outstanding borrowings					$ 24,375,000	$ 5,000,000
Term Loan [Member]
Debt Instrument [Line Items]
Outstanding borrowings		$ 80,000,000			80,000,000		$ 86,900,000
Senior Secured Term Loan [Member]
Debt Instrument [Line Items]
Debt issuance costs		400,000			400,000		600,000
Senior Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Outstanding borrowings							17,500,000
Amount available under credit facility		47,900,000			47,900,000		30,300,000
Repayment of outstanding borrowings			$ 17,500,000
Interest expense		400,000		$ 500,000	1,200,000	$ 1,900,000
Senior Secured Revolving Credit Facility [Member] | Other Assets [Member]
Debt Instrument [Line Items]
Debt issuance costs		200,000			200,000		300,000
Senior Secured Revolving Credit Facility [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Outstanding borrowings		$ 2,100,000			$ 2,100,000		$ 2,200,000
Credit Agreement with Certain Lenders [Member]
Debt Instrument [Line Items]
Credit facility term	5 years
Credit facility maturity date	Jul. 23, 2023
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] | LIBOR Plus [Member]
Debt Instrument [Line Items]
Credit facility current interest rate					1.375%		1.375%

Debt - Schedule of Future Minim

Debt - Schedule of Future Minimum Principal Payment Obligations (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Debt Instrument [Line Items]
Less: Current portion of long-term debt	$ (9,738)	$ (9,090)
Long-term debt	69,867	$ 94,671
Senior Secured Term Loan and Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Remainder of 2022	2,500
2023	10,000
2024	67,500
Total minimum debt payments	80,000
Less: Debt issuance costs	(395)
Less: Current portion of long-term debt	(9,738)
Long-term debt	$ 69,867

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Mar. 31, 2021
Security Incident [Member]
Commitments And Contingencies [Line Items]
Pre-tax expenses of security incident, net of anticipated insurance recoveries	$ 0	$ 0	$ 800,000

Restructuring - Additional Info

Restructuring - Additional Information (Detail) - USD ($)	Jan. 28, 2021	Dec. 31, 2021	Mar. 31, 2021
Restructuring And Related Activities [Abstract]
Restructuring plan, percentage reduction in workforce	4.00%
Total pre-tax restructuring charges			$ 3,300,000
Restructuring charges		$ 0	3,700,000
Restructuring charges, other adjustments			$ 400,000

Restructuring - Schedule of Res

Restructuring - Schedule of Restructuring Liability Balance (Detail) - Severance and Related Costs [Member] $ in Thousands	9 Months Ended
	Dec. 31, 2021USD ($)
Restructuring Cost And Reserve [Line Items]
Balance as of March 31, 2021	$ 398
Cash payments	(398)
Balance as of December 31, 2021	$ 0

Segment and Geographic Inform_3

Segment and Geographic Information - Summary of Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 151,599	$ 129,636	$ 441,381	$ 367,505
United States [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	78,128	65,942	223,564	189,864
United Kingdom [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	42,154	36,977	124,270	105,464
South Africa [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	15,017	13,732	45,676	37,419
Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 16,300	$ 12,985	$ 47,871	$ 34,758

Segment and Geographic Inform_4

Segment and Geographic Information - Summary of Property and Equipment, Net by Geographic Location (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	$ 91,066	$ 92,891
United States [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	40,882	40,129
United Kingdom [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	27,611	28,892
South Africa [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	6,650	7,942
Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Property, plant and equipment, net	$ 15,923	$ 15,928

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Income Taxes [Line Items]
Provision for income taxes	$ 1,705,000	$ 1,155,000	$ 4,884,000	$ 2,350,000
Income (loss) before income taxes	15,523,000	11,944,000	46,357,000	26,327,000
Excess tax benefits on share-based compensation	1,300,000	1,400,000	3,400,000	4,500,000
Liabilities for uncertain tax positions	0		0
Liabilities for uncertain tax positions that would impact effective tax rate if recognized	$ 0		$ 0
MessageControl [Member]
Income Taxes [Line Items]
Provision for income taxes		$ (600,000)		$ (600,000)