Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Mar. 15, 2024	Jun. 30, 2023
Document And Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2023
Entity File Number	001-37544
Entity Registrant Name	ARMATA PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	91-1549568
Entity Address, Address Line One	5005 McConnell Avenue
Entity Address, City or Town	Los Angeles
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	90066
City Area Code	310
Local Phone Number	665-2928
Title of 12(b) Security	Common Stock
Trading Symbol	ARMP
Security Exchange Name	NYSEAMER
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		36,148,539
Entity Public Float			$ 12.5
Entity Central Index Key	0000921114
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false
ICFR Auditor Attestation Flag	false
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	San Diego, California
Document Financial Statement Error Correction [Flag]	false