Represents the number of amendments to the Broker-Dealer Acquisition Agreement.

No definition available.

Name:	atch_BusinessCombinationNumberOfAmendmentsToBrokerDealerAcquisitionAgreement
Namespace Prefix:	atch_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the conversion term at the option of holder after the closing date.

+ References

No definition available.

+ Details

Name:	atch_ConversionTermAtOptionOfHolderAfterClosingDate
Namespace Prefix:	atch_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Conversion rate of debt instrument, as a percentage of the trailing specified trading day volume weighted average price of the Common Stock ("VWAP") prior to conversion.

+ References

No definition available.

+ Details

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Namespace Prefix:	atch_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Conversion rate of debt instrument, as a percentage of the trailing specified trading day volume weighted average price of the Common Stock ("VWAP") prior to conversion, if an event of default occurs and is continuing.

+ References

No definition available.

+ Details

Name:	atch_DebtInstrumentConvertibleConversionRateAsPercentageOfTrailingSpecifiedTradingDayVolumeWeightedAverageSharePrice.IfEventOfDefaultOccursAndIsContinuing
Namespace Prefix:	atch_
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Balance Type:	na
Period Type:	duration

- Definition

Number of trailing trading days over which volume weighted average price of the Common Stock ("VWAP") is considered for determination of conversion rate of debt instrument.

+ References

No definition available.

+ Details

Name:	atch_DebtInstrumentConvertibleConversionRateNumberOfTradingDaysOverWhichVolumeWeightedAverageSharePriceIsConsidered
Namespace Prefix:	atch_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest payable on debt in shares as a percentage of the trailing specified trading day volume weighted average price of the Common Stock ("VWAP") prior to payment.

+ References

No definition available.

+ Details

Name:	atch_DebtInstrumentInterestPayableInSharesAsPercentageOfTrailingSpecifiedTradingDayVolumeWeightedAverageSharePrice
Namespace Prefix:	atch_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the term to file registration statement with the SEC registering the resale of the shares of Common Stock issuable upon conversion of the Notes.

+ References

No definition available.

+ Details

Name:	atch_TermToFileRegistrationStatementWithSec
Namespace Prefix:	atch_
Data Type:	xbrli:durationItemType
Balance Type:	na
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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479907/805-20-50-5

+ Details

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

- Definition

Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-Publisher FASB
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-Paragraph 7
-SubTopic 30
-Topic 805
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-URI https://asc.fasb.org//1943274/2147479637/805-30-30-7

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to items of consideration transferred in connection with a business combination for which the initial accounting was incomplete.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
-Paragraph 4A
-Subparagraph (c)
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
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-Subparagraph (SX 210.5-02.22(a)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
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-SubTopic 10
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-13

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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Data Type:	na
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- Details

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ACQUISITION OF WILSON-DAVIS - Broker-Dealer Acquisition Agreement (Details)			3 Months Ended
	Feb. 07, 2024 USD ($) D item	Feb. 09, 2021	Mar. 31, 2024 USD ($)
ACQUISITION OF WILSON-DAVIS
Number of amendments to the Broker-Dealer Acquisition Agreement \| item	2
Reduction in total purchase price payable	$ 5,000,000
Cash payable	$ 8,000,000		$ 7,127,569
Maturity (in days)		185 days
Conversion term at the option of holder after the closing date	6 months
WILSON-DAVIS
ACQUISITION OF WILSON-DAVIS
Cash payable	$ 7,127,569
Term to file registration statement with the SEC	30 days
WILSON-DAVIS \| Short term
ACQUISITION OF WILSON-DAVIS
Short-term and long-term notes	$ 5,000,000
Maturity (in days)	90 days
Interest rate (in percent)	9.00%
Interest payable in shares, as a percentage of trailing specified trading day VWAP (in percent)	90.00%
Conversion rate, Number of trading days over which the VWAP is considered \| D	7
WILSON-DAVIS \| Long term
ACQUISITION OF WILSON-DAVIS
Short-term and long-term notes	$ 7,971,197
Maturity (in days)	24 months
Interest rate (in percent)	13.00%
Interest payable in shares, as a percentage of trailing specified trading day VWAP (in percent)	90.00%
Conversion rate, as a percentage of trailing specified trading day VWAP (in percent)	90.00%
Conversion rate, Number of trading days over which the VWAP is considered \| D	7
Conversion rate, as a percentage of trailing seven-trading day VWAP, if an event of default occurs and is continuing (in percent)	85.00%