Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 01, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Registrant Name	CSB BANCORP INC /OH
Trading Symbol	CSBB
Entity Central Index Key	0000880417
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
Title of 12(b) Security	Common Shares, $6.25 par value
Security Exchange Name	NONE
Entity Common Stock, Shares Outstanding		2,725,524
Entity File Number	0-21714
Entity Incorporation, State or Country Code	OH
Entity Tax Identification Number	34-1687530
Entity Address, Address Line One	91 North Clay Street
Entity Address, Address Line Two	P.O. Box 232
Entity Address, City or Town	Millersburg
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	44654
City Area Code	330
Local Phone Number	674-9015
Document Quarterly Report	true
Document Transition Report	false