Name:	amba_AggregateIntrinsicValueOfUnvestedRestrictedStockUnits
Namespace Prefix:	amba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Closing market price of ordinary shares on NASDAQ on the last day of reporting period.

No definition available.

Name:	amba_ClosingMarketPriceOfOrdinarySharesOnNasdaqOnLastDayOfReportingPeriod
Namespace Prefix:	amba_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

Contribution to employee stock purchase plan as percentage of employee salary.

No definition available.

Name:	amba_ContributionToEmployeeStockPurchasePlanAsPercentageOfEmployeeSalary
Namespace Prefix:	amba_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Exercised but unvested stock options repurchased as of the reporting date.

No definition available.

Name:	amba_ExercisedButUnvestedStockOptionsRepurchasedDuringReportingPeriod
Namespace Prefix:	amba_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Exercise price of stock options as minimum percentage of fair market value at grant date.

No definition available.

Name:	amba_ExercisePriceOfStockOptionsAsMinimumPercentageOfFairMarketValueAtGrantDate
Namespace Prefix:	amba_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Maximum period that stock options can be exercised.

No definition available.

Name:	amba_MaximumPeriodThatStockOptionCanBeExercised
Namespace Prefix:	amba_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Purchase price of ordinary shares as percentage of lower of the closing market price of ordinary shares on first day of offering period or on last day of purchase period.

No definition available.

Name:	amba_PercentageOfPurchasePlanPricePerShareEqualToFairMarketValue
Namespace Prefix:	amba_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Unvested stock options subject to repurchase.

No definition available.

Name:	amba_UnvestedStockOptionsSubjectToRepurchase
Namespace Prefix:	amba_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Vesting period of restricted stock units for new hire.

No definition available.

Name:	amba_VestingPeriodForRestrictedStockUnitsNewHire
Namespace Prefix:	amba_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Vesting period of stock option for new hire.

No definition available.

Name:	amba_VestingPeriodOfStockOptionsNewHire
Namespace Prefix:	amba_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Voting power ownership percentage.

No definition available.

Name:	amba_VotingPowerOwnershipPercentage
Namespace Prefix:	amba_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Aggregate unrecognized cost of share-based awards, other than options, made to employees under an equity-based compensation plan, that have yet to vest.

No definition available.

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

Aggregate unrecognized cost of option awards made to employees under a stock option plan or plans, that have yet to vest.

No definition available.

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

Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.