XML 120 R107.htm IDEA: XBRL DOCUMENT
v3.19.1

Off-Balance Sheet Activities (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Risks and Uncertainties [Abstract] |  |
Unused lines of credit and letters of credit - fixed rate | $ 20,036 | $ 9,033
Unused lines of credit and letters of credit - variable rate | 103,978 | 104,257
Commitments to fund loans (at market rates) - fixed rate | 20,997 | 8,663
Commitments to fund loans (at market rates) - variable rate | $ 1,421 | $ 1,225

X
- Definition Reflects the amount of cash required to fund unused lines and letters of credt at stated interest rates. + References No definition available. + Details
Name: | cofs_UnusedLinesOfCreditAndLettersOfCreditFixedRate
Namespace Prefix: | cofs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the amount of cash required to fund unused lines and letters of credt at variable interest rates. + References No definition available. + Details
Name: | cofs_UnusedLinesOfCreditAndLettersOfCreditVariableRate
Namespace Prefix: | cofs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at stated interest rates. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61044-112788 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61082-112788 + Details
Name: | us-gaap_LoansAndLeasesReceivableCommitmentsFixedRates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at interest rates that increase or decrease depending on certain facts or circumstances. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61082-112788 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 825 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=108315417&loc=d3e61044-112788 + Details
Name: | us-gaap_LoansAndLeasesReceivableCommitmentsVariableRates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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