Organization and Description of the Business (Details) $ in Millions		9 Months Ended
May 09, 2019 USD ($) shares	Sep. 30, 2019
Reverse stock split ratio		0.0714
C3J [Member]
Number of shares issued per common stock outstanding \| shares	6,906.0000
Reverse stock split ratio	0.0714
Anticipated purchase of common shares upon completion of merger \| $	$ 10.0
Percentage of ownership	76.00%
AmpliPhi Biosciences Corporation [Member]
Percentage of ownership	24.00%

Represents the anticipated purchase of common shares upon completion of the business combination.

No definition available.

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

- Definition

The number of common shares issued to each common stock outstanding in consideration for the business combination.

+ References

No definition available.

+ Details

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

- Definition

The percentage of aggregate number of shares of common stock and security holders.

+ References

No definition available.

+ Details

Name:	armp_CommonStockPercentageOfAggregateNumberOfSharesAndSecurityHolders
Namespace Prefix:	armp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
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- Details

Name:	dei_LegalEntityAxis=armp_AmpliphiBiosciencesCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: