Additional grant revenue to be recognized.

No definition available.

Name:	armp_AdditionalGrantRevenueToBeRecognized
Namespace Prefix:	armp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the period for which the company ceases to use commercially reasonable efforts directed to the development of the product.

+ References

No definition available.

+ Details

Name:	armp_AwardAgreementInterruptionPeriod
Namespace Prefix:	armp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of cash inflow associated with government grants.

+ References

No definition available.

+ Details

Name:	armp_ProceedsFromGovernmentGrants
Namespace Prefix:	armp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) in income from government assistance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483507/832-10-50-3

+ Details

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

- Definition

Amount of increase in asset from government assistance, classified as current.

+ References

+ Details

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

- Definition

Amount of government assistance awarded that comprises amount received, receivable, and to be received unless condition for government assistance is not met. Includes, but is not limited to, government grant, assistance, incentive, award, subsidy, and loan.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483507/832-10-50-3

+ Details

Name:	us-gaap_GovernmentAssistanceAwardAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

+ Details

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

- Definition

Duration of government assistance transaction, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 832
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483507/832-10-50-4

+ Details

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

- Definition

Carrying amount as of the balance sheet date of amounts due under the terms of governmental, corporate, or foundation grants. For classified balance sheets, represents the current amount receivable, that is amounts expected to be collected within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(a)(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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

- Details

Name:	us-gaap_GovernmentAssistanceTypeAxis=armp_MedicalTechnologyEnterpriseConsortiumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GovernmentAssistanceTypeAxis=armp_AwardAgreementWithCysticFibrosisFoundationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Grant and Awards (Narrative) (Details) - USD ($)				1 Months Ended	3 Months Ended		9 Months Ended
Grant and Awards (Narrative) (Details) - USD ($)	Sep. 29, 2022	Jun. 15, 2020	Mar. 13, 2020	Jul. 31, 2024	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Mar. 31, 2024	Dec. 31, 2023
MTEC Grant
Government Assistance [Line Items]
Revenue from grants	$ 16,300,000	$ 15,000,000.0		$ 21,600,000					$ 16,300,000
Government assistance, transaction duration		3 years
Increase in expected revenue from grants	$ 1,300,000			$ 5,300,000
Grant revenue from the MTEC Agreement					$ 3,000,000.0	$ 1,200,000	$ 3,900,000	$ 3,000,000.0
Additional grant revenue to be recognized					5,300,000
Grants receivable					1,600,000		1,600,000			$ 1,500,000
CFF Therapeutics Development Award
Government Assistance [Line Items]
Grant revenue from the MTEC Agreement					$ 0	$ 0	$ 0	$ 0
Proceeds from governments grants			$ 1,000,000.0
Award agreement interruption period			360 days
CFF Therapeutics Development Award \| Maximum
Government Assistance [Line Items]
Revenue from grants			$ 5,000,000.0