Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2023	Apr. 26, 2024	Jun. 30, 2023
Document Information [Line Items]
Document Type	10-K/A
Amendment Flag	true
Document Period End Date	Dec. 31, 2023
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Trading Symbol	FATH
Entity Registrant Name	FATHOM DIGITAL MANUFACTURING CORPORATION
Entity Central Index Key	0001836176
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	true
Document Financial Statement Restatement Recovery Analysis [Flag]	false
Entity Current Reporting Status	Yes
Entity Public Float			$ 18,431,182
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity File Number	001-39994
Entity Tax Identification Number	98-1571400
Entity Address, Address Line One	1050 Walnut Ridge Drive
Entity Address, City or Town	Hartland
Entity Address, State or Province	WI
Entity Address, Postal Zip Code	53029
City Area Code	262
Local Phone Number	367-8254
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Security Exchange Name	NYSE
Document Annual Report	true
Document Transition Report	false
Auditor Name	Grant Thornton, LLP
Auditor Firm ID	248
Auditor Location	Milwaukee, WI
Amendment Description	This Amendment No. 1 on Form 10-K/A (this “Form 10-K Amendment”) amends the Annual Report on Form 10-K for the fiscal year ended December 31, 2023, of Fathom Digital Manufacturing Corporation (“Fathom,” the “Company,” “we,” “us” or “our”), originally filed with the U.S. Securities and Exchange Commission (the “SEC”) on April 16, 2024 (the “Original Report”). The purpose of this Form 10-K Amendment is to include the information required by Items 10 through 14 of Part III of Form 10-K. This information was previously omitted from the Original Report in reliance on General Instruction G(3) to Form 10-K. We are filing this Form 10-K Amendment to present the information required by Part III of Form 10-K as we will not file our definitive proxy statement relating to our 2024 annual meeting within 120 days of the end of our fiscal year ended December 31, 2023. In accordance with Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), Part III of the Original Report, consisting of Items 10 through 14, is hereby amended and restated in its entirety. This Form 10-K Amendment consists solely of the preceding cover page, this explanatory note, the information required by Part III, namely Items 10 through 14 of Form 10-K, a signature page and the certifications required to be filed as exhibits. We are also amending Part IV of Form 10-K to add those certifications, which are attached hereto. This Form 10-K Amendment does not amend, modify or otherwise update any other information in the Original Report. Accordingly, this Form 10-K Amendment should be read in conjunction with the Original Report. In addition, this Form 10-K Amendment does not reflect events that may have occurred subsequent to the Original Report date. The Original Report, as amended by this Form 10-K Amendment, is referred to herein as the Annual Report.
Class A Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,649,866
Class B Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		3,327,379