Fair Values of Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Commitments to extend credit and letters of credit	$ 236	$ 211

Commitments to extend credit and letters of credit.

No definition available.

Name:	csbb_CommitmentsToExtendCreditAndLettersOfCredit
Namespace Prefix:	csbb_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant