Cover - shares	3 Months Ended
	Mar. 31, 2023	May 01, 2023
Cover [Abstract]
Entity Registrant Name	Smith-Midland Corporation
Entity Central Index Key	0000924719
Document Type	10-Q
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Document Period End Date	Mar. 31, 2023
Entity Filer Category	Non-accelerated Filer
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2023
Entity Common Stock Shares Outstanding		5,256,413
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	1-13752
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	54-1727060
Entity Address Address Line 1	5119 Catlett Road
Entity Address Address Line 2	P.O. Box 300
Entity Address City Or Town	Midland
Entity Address State Or Province	VA
Entity Address Postal Zip Code	22728
City Area Code	540
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