Cover - USD ($)	12 Months Ended
	Dec. 31, 2024	May 02, 2025	Jun. 30, 2024
Cover [Abstract]
Entity Registrant Name	Smith-Midland Corporation
Entity Central Index Key	0000924719
Document Type	10-K
Amendment Flag	false
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Well Known Seasoned Issuer	No
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Document Period End Date	Dec. 31, 2024
Entity Filer Category	Non-accelerated Filer
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2024
Entity Common Stock Shares Outstanding		5,304,606
Entity Public Float			$ 77,253,882
Document Annual Report	true
Document Transition Report	false
Document Fin Stmt Error Correction Flag	false
Entity File Number	1-13752
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	54-1727060
Entity Address Address Line 1	P.O. Box 300
Entity Address Address Line 2	5119 Catlett Road
Entity Address City Or Town	Midland
Entity Address State Or Province	VA
Entity Address Postal Zip Code	22728
City Area Code	540
Icfr Auditor Attestation Flag	false
Auditor Location	Richmond, Virginia
Auditor Firm Id	243
Local Phone Number	439-3266
Security 12b Title	Common Stock, $0.01 par value per share
Trading Symbol	SMID
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Auditor Name	BDO USA, P.C.