Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 29, 2021	Jun. 30, 2020
Document and Entity Information
Document Type	10-K
Document Period End Date	Dec. 31, 2020
Entity Registrant Name	SANDSTON CORP
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	true
Title of 12(b) Security	Common Stock, no par value
Trading Symbol	SDON
Entity Common Stock, Shares Outstanding		17,707,472
Entity Public Float			$ 396,000
Entity Central Index Key	0000892832
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31