XML 109 R95.htm IDEA: XBRL DOCUMENT
v3.23.1

Note 10 - Borrowings - Federal Home Loan Bank Advances (Details) (Parentheticals) | Dec. 31, 2021
--- | ---
Federal Home Loan Bank Advances Maturing January 2023 [Member] |
Interest rate | 4.16%
Federal Home Loan Bank Advances Maturing January 2022 [Member] |
Interest rate | 0.21%

X
- Definition Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123599511&loc=d3e64711-112823 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 + Details
Name: | us-gaap_FederalHomeLoanBankAdvancesBranchOfFHLBBankInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=cofs_FederalHomeLoanBankAdvancesMaturingJanuary2023Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=cofs_FederalHomeLoanBankAdvancesMaturingJanuary2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |