XML 47 R41.htm IDEA: XBRL DOCUMENT
v3.24.3

Loans and Allowance for Credit Losses - Schedule of Information Regarding Credit Exposure (Parenthetical) (Details) - USD ($) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Dec. 31, 2023
Receivables [Abstract] |  |  |
Financing receivable originated checking accounts writeoffs | $ 473,000 | $ 377,000 | $ 480,000
Financing receivable originated checking accounts writeoffs annualized | $ 631,000 | $ 503,000 |

X
- Definition Financing receivable originated checking accounts writeoffs. + References No definition available. + Details
Name: | cofs_FinancingReceivableOriginatedCheckingAccountsWriteoffs
Namespace Prefix: | cofs_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Financing receivable originated checking accounts writeoffs annualized. + References No definition available. + Details
Name: | cofs_FinancingReceivableOriginatedCheckingAccountsWriteoffsAnnualized
Namespace Prefix: | cofs_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_ReceivablesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration