Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2023	Mar. 21, 2024	Jun. 30, 2023
Document Information [Line Items]
Entity Central Index Key	0000086115
Entity Registrant Name	SAFEGUARD SCIENTIFICS INC
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Document Transition Report	false
Entity File Number	1-5620
Entity Incorporation, State or Country Code	PA
Entity Tax Identification Number	23-1609753
Entity Address, Address Line One	150 N. Radnor Chester Road
Entity Address, City or Town	Radnor
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19087
City Area Code	610
Local Phone Number	293-0600
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	Yes
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 21,248,137
Entity Common Stock, Shares Outstanding		16,722,994
Auditor Firm ID	248
Auditor Name	GRANT THORNTON LLP
Auditor Location	Philadelphia, Pennsylvania