Represents the number of common stock shares subject aggregate of sponsor surrendered.

No definition available.

Name:	atacu_AggregateOfSponsorSharesSurrendered
Namespace Prefix:	atacu_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

"Number of shares of the company that are subject to forfeiture represented as a percentage of issued and outstanding stock as a result of partial exercise of over-allotment option. "

+ References

No definition available.

+ Details

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Namespace Prefix:	atacu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the maximum number of common stock shares subject to forfeiture.

+ References

No definition available.

+ Details

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Namespace Prefix:	atacu_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares of the company that were forfeited during the period.

+ References

No definition available.

+ Details

Name:	atacu_NumberOfSharesForfeited
Namespace Prefix:	atacu_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares of the company that were no longer subject to forfeiture.

+ References

No definition available.

+ Details

Name:	atacu_NumberOfSharesNoLongerSubjectToForfeiture
Namespace Prefix:	atacu_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of shares transferred.

+ References

No definition available.

+ Details

Name:	atacu_SharesTransferred
Namespace Prefix:	atacu_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The threshold period after the business combination in which the 20 trading days within any 30 trading day period commences for the transfer, assigning or sale of any shares of the company, after the completion of the initial business combination.

+ References

No definition available.

+ Details

Name:	atacu_ThresholdPeriodAfterBusinessCombinationInWhichSpecifiedTradingDaysWithinAnySpecifiedTradingDayPeriodCommences
Namespace Prefix:	atacu_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The threshold period for not to transfer, assign or sell any of the shares or warrants, after the completion of the initial business combination.

+ References

No definition available.

+ Details

Name:	atacu_ThresholdPeriodForNotToTransferAssignOrSellAnySharesOrWarrantsAfterCompletionOfInitialBusinessCombination
Namespace Prefix:	atacu_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Price of the entity's common stock which would be required to be attained to trigger the transfer, assign or sale of any shares or warrants of the company, after the completion of the initial business combination.

+ References

No definition available.

+ Details

Name:	atacu_TransferAssignOrSellAnySharesOrWarrantsAfterCompletionOfInitialBusinessCombinationStockPriceTrigger
Namespace Prefix:	atacu_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- 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

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

- Definition

Cash received on stock transaction after deduction of issuance costs.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockConsiderationReceivedOnTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

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

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_OverAllotmentOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_BeneficialOwnerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

RELATED PARTY TRANSACTIONS - Founder Shares (Details) - USD ($)					1 Months Ended
	Dec. 07, 2020	Oct. 21, 2020	Oct. 19, 2020	Sep. 01, 2020	Sep. 30, 2020	Nov. 09, 2020
Related Party Transaction [Line Items]
Common stock, shares subject to forfeiture, as a percent of issued and outstanding shares (as a percent)					20.00%
Threshold period for not to transfer, assign or sell any of their shares or warrants after the completion of the initial business combination					150 days
Stock price trigger to transfer, assign or sell any shares or warrants of the company, after the completion of the initial business combination (in dollars per share)					$ 12.00
Maximum
Related Party Transaction [Line Items]
Threshold period after the business combination in which the 20 trading days within any 30 trading day period commences					20 days
Subsequent event
Related Party Transaction [Line Items]
Common stock, shares issued	6,875,000
Common stock, shares outstanding	6,875,000
Number of shares were forfeited	312,500
Over-allotment \| Subsequent event
Related Party Transaction [Line Items]
Number of shares no longer subject to forfeiture						625,000
Number of shares were forfeited	312,500
Sponsor
Related Party Transaction [Line Items]
Threshold period after the business combination in which the 20 trading days within any 30 trading day period commences					30 days
Sponsor \| Subsequent event
Related Party Transaction [Line Items]
Shares transferred			25,000
Class B common stock
Related Party Transaction [Line Items]
Common stock, shares issued					7,187,500
Common stock, shares outstanding				8,625,000	7,187,500
Class B common stock \| Subsequent event
Related Party Transaction [Line Items]
Common stock, shares outstanding		7,187,500
Class B common stock \| Over-allotment
Related Party Transaction [Line Items]
Shares subject to forfeiture					312,500
Class B common stock \| Sponsor
Related Party Transaction [Line Items]
Consideration received				$ 25,000
Shares issued				8,625,000
Class B common stock \| Sponsor \| Subsequent event
Related Party Transaction [Line Items]
Consideration received		$ 0
Shares surrendered		1,437,500