Debt instrument covenant representing the minimum market capitalization to remain in compliance.

No definition available.

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Namespace Prefix:	alt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage of funded loan amount that is paid as end of term charge under debt agreement.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of funded loan amount that is paid as facility charge under debt agreement.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents maximum number of tranches under which loan is available under debt agreement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents percentage of prepayment charge on outstanding principal amount at the time of repayment under debt agreement.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Prepayment term 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

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Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

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- 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

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+ Details

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicates type of variable interest rate on debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of interest expense classified as nonoperating.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Balance Type:	debit
Period Type:	duration

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- Details

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- Details

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Term Loan (Details) $ in Thousands		3 Months Ended		6 Months Ended
Term Loan (Details) $ in Thousands	May 13, 2025 USD ($) tranche	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)
Term Loan
Interest expense		$ 264	$ 1	$ 265	$ 2
Interest rate until December 31, 2025
Term Loan
Interest Rate (as a percent)	9.95%
Interest rate thereafter
Term Loan
Interest Rate (as a percent)	9.45%
Prepayment made within the twelve months
Term Loan
Prepayment charge	3.00%
Prepayment term	12 months
Prepayment made within the twenty four months
Term Loan
Prepayment charge	2.00%
Prepayment term	24 months
Prepayment made within the thirty six months
Term Loan
Prepayment charge	1.00%
Prepayment term	36 months
Prepayment made thereafter
Term Loan
Prepayment charge	0.00%
Term loan
Term Loan
Number of tranches \| tranche	4
Principal amount	$ 100,000
Basis spread on variable rate	2.45%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:BaseRateMember
End of term charge	6.25%
Facility charge	1.00%
Interest rate	14.40%
Interest expense		$ 300		$ 300
Maturity date	Jan. 01, 2029
Debt instrument covenant, minimum market capitalization	$ 800,000
First term loan tranche
Term Loan
Principal amount	15,000
Second term loan tranche
Term Loan
Principal amount	25,000
Third term loan tranche
Term Loan
Principal amount	15,000
Fourth term loan tranche
Term Loan
Principal amount	$ 45,000