Summary of Significant Accounting Policies - Additional Information (Detail)	9 Months Ended
Sep. 30, 2020
Accounting Policies [Abstract]
Percentage of revenue not within scope of ASC 606	89.00%

Percentage of revenue not from contract with customer.

No definition available.

Name:	csbb_PercentageOfRevenueNotFromContractWithCustomer
Namespace Prefix:	csbb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration