Option Indexed To Issuer's Equity, Cap Price

No definition available.

Name:	mdb_OptionIndexedToIssuersEquityCapPrice
Namespace Prefix:	mdb_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of subsequent adjustments to additional paid in capital for convertible financial instruments where a component of equity and a component of debt are recognized.

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum number of shares that could be issued to net share settle a contract, if applicable. If a contract does not have a fixed or determinable maximum number of shares that may be required to be issued, disclose the fact that a potentially infinite number of shares could be issued to settle the contract.

+ References

+ Details

Name:	us-gaap_OptionIndexedToIssuersEquityShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise or strike price stated in the contract for options indexed to the issuer's equity shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 40
-Section 50
-Paragraph 5
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=6445032&loc=d3e90205-114008

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(1)
-URI http://asc.fasb.org/extlink&oid=109262807&loc=d3e22047-110879

+ Details

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
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Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_ConvertibleDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mdb_ConvertibleNotesDue2026Member
Namespace Prefix:
Data Type:	na
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Period Type:

Convertible Senior Notes - Capped Calls (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	1 Months Ended	2 Months Ended	12 Months Ended
	Jan. 31, 2020	Jul. 31, 2018	Jan. 31, 2020
Option Indexed to Issuer's Equity [Line Items]
Purchase of capped calls		$ 37,100	$ 303,929
Capped Calls
Option Indexed to Issuer's Equity [Line Items]
Strike price (in dollars per share)		$ 68.15
Cap price (in dollars per share)		$ 106.90
Capped Calls \| Class A Common Stock
Option Indexed to Issuer's Equity [Line Items]
Underlying capped calls (in shares)		4.4
Convertible Debt \| 2026 Notes
Option Indexed to Issuer's Equity [Line Items]
Strike price (in dollars per share)	$ 211.20
Cap price (in dollars per share)	$ 296.42
Underlying capped calls (in shares)	5.4
Purchase of capped calls	$ 93,800