Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 14, 2022	Jun. 30, 2021
Cover [Abstract]
Entity Central Index Key	0000065596
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Document Transition Report	false
Entity File Number	0-5703
Entity Registrant Name	Siebert Financial Corp
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	11-1796714
Entity Address, Address Line One	535 Fifth Avenue
Entity Address, Address Line Two	4th Floor
Entity Address, City or Town	NY
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10017
City Area Code	212
Local Phone Number	644-2400
Title of 12(b) Security	Common Stock - $0.01 par value
Trading Symbol	SIEB
Name of Exchange on which Security is Registered	NASDAQ
Entity Well-Known Seasoned Issuer	No
Entity Voluntary Filers	No
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
Entity Shell Company	false
Auditor Attestation Flag	false
Entity Public Float			$ 64,193,000
Entity Common Stock, Shares Outstanding		32,403,235
Auditor Name	Baker Tilly US, LLP
Auditor Location	New York, New York
Auditor Firm Id	23