Fair Value Measurements - Schedule of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Jan. 31, 2019
Financial Assets:
Marketable securities	$ 572,060	$ 112,777
Commercial paper
Financial Assets:
Marketable securities	37,894	1,243
Corporate bonds
Financial Assets:
Marketable securities		53,214
Agency bonds
Financial Assets:
Marketable securities	141,163	32,604
Corporate and other debt securities
Financial Assets:
Marketable securities	321,166
U.S. government agency securities
Financial Assets:
Marketable securities	71,837	24,017
Treasury bills
Financial Assets:
Marketable securities		1,699
Fair Value, Recurring Basis
Financial Assets:
Cash equivalents	111,479	78
Marketable securities	572,060	112,777
Total financial assets		115,199
Financial Liabilities:
Convertible promissory notes – derivative liabilities included in other liabilities, noncurrent		163
Total financial liabilities		163
Fair Value, Recurring Basis \| Commercial paper
Financial Assets:
Marketable securities	37,894	1,243
Fair Value, Recurring Basis \| Corporate bonds
Financial Assets:
Marketable securities		53,214
Fair Value, Recurring Basis \| Agency bonds
Financial Assets:
Marketable securities	141,163	32,604
Fair Value, Recurring Basis \| Corporate and other debt securities
Financial Assets:
Marketable securities	321,166
Fair Value, Recurring Basis \| U.S. government agency securities
Financial Assets:
Marketable securities	71,837	24,017
Fair Value, Recurring Basis \| Treasury bills
Financial Assets:
Marketable securities		1,699
Fair Value, Recurring Basis \| Certificates of deposit
Financial Assets:
Certificate of deposit included in prepaid expenses and other current and noncurrent assets	100	200
Other assets, noncurrent	2,301	2,144
Total financial assets	685,940
Fair Value, Recurring Basis \| Money market funds
Financial Assets:
Cash equivalents	96,486	78
Fair Value, Recurring Basis \| Commercial paper
Financial Assets:
Cash equivalents	4,994
Fair Value, Recurring Basis \| Agency bonds
Financial Assets:
Cash equivalents	9,999
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1
Financial Assets:
Cash equivalents	96,486	78
Marketable securities	0	0
Total financial assets	96,486	78
Financial Liabilities:
Convertible promissory notes – derivative liabilities included in other liabilities, noncurrent		0
Total financial liabilities		0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| Commercial paper
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| Corporate bonds
Financial Assets:
Marketable securities		0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| Agency bonds
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| Corporate and other debt securities
Financial Assets:
Marketable securities	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| U.S. government agency securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| Treasury bills
Financial Assets:
Marketable securities		0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| Certificates of deposit
Financial Assets:
Certificate of deposit included in prepaid expenses and other current and noncurrent assets	0	0
Other assets, noncurrent	0	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| Money market funds
Financial Assets:
Cash equivalents	96,486	78
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| Commercial paper
Financial Assets:
Cash equivalents	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 1 \| Agency bonds
Financial Assets:
Cash equivalents	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2
Financial Assets:
Cash equivalents	14,993	0
Marketable securities	572,060	112,777
Total financial assets	589,454	115,121
Financial Liabilities:
Convertible promissory notes – derivative liabilities included in other liabilities, noncurrent		0
Total financial liabilities		0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| Commercial paper
Financial Assets:
Marketable securities	37,894	1,243
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| Corporate bonds
Financial Assets:
Marketable securities		53,214
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| Agency bonds
Financial Assets:
Marketable securities	141,163	32,604
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| Corporate and other debt securities
Financial Assets:
Marketable securities	321,166
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| U.S. government agency securities
Financial Assets:
Marketable securities	71,837	24,017
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| Treasury bills
Financial Assets:
Marketable securities		1,699
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| Certificates of deposit
Financial Assets:
Certificate of deposit included in prepaid expenses and other current and noncurrent assets	100	200
Other assets, noncurrent	2,301	2,144
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| Money market funds
Financial Assets:
Cash equivalents	0	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| Commercial paper
Financial Assets:
Cash equivalents	4,994
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 2 \| Agency bonds
Financial Assets:
Cash equivalents	9,999
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3
Financial Assets:
Cash equivalents	0	0
Marketable securities	0	0
Total financial assets	0	0
Financial Liabilities:
Convertible promissory notes – derivative liabilities included in other liabilities, noncurrent		163
Total financial liabilities		163
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| Commercial paper
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| Corporate bonds
Financial Assets:
Marketable securities		0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| Agency bonds
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| Corporate and other debt securities
Financial Assets:
Marketable securities	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| U.S. government agency securities
Financial Assets:
Marketable securities	0	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| Treasury bills
Financial Assets:
Marketable securities		0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| Certificates of deposit
Financial Assets:
Certificate of deposit included in prepaid expenses and other current and noncurrent assets	0	0
Other assets, noncurrent	0	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| Money market funds
Financial Assets:
Cash equivalents	0	$ 0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| Commercial paper
Financial Assets:
Cash equivalents	0
Fair Value, Recurring Basis \| Fair Value, Inputs, Level 3 \| Agency bonds
Financial Assets:
Cash equivalents	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

+ Details

Name:	us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

+ Details

Name:	us-gaap_DerivativeLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value of financial and nonfinancial obligations.

+ References

+ Details

Name:	us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value portion of other assets.

+ References

No definition available.

+ Details

Name:	us-gaap_OtherAssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Prepaid expenses and other current assets, fair value disclosure.

+ References

No definition available.

+ Details

Name:	zm_PrepaidExpensesAndOtherCurrentAssetsFairValueDisclosure
Namespace Prefix:	zm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=zm_CorporateAndOtherDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasuryBillSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CashAndCashEquivalentsAxis=us-gaap_MunicipalBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: