XML 84 R65.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Loans and Allowance for Loan Losses (Details 4) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2016 USD ($) Loan | Dec. 31, 2015 USD ($) Loan
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | Loan | 3 | 6
Pre-Modification Outstanding Recorded Investment | $ 260 | $ 634
Post Modification Oustanding Recorded Investment | $ 260 | $ 634
Agricultural [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | Loan | 1 |
Pre-Modification Outstanding Recorded Investment | $ 105 |
Post Modification Oustanding Recorded Investment | $ 105 |
Commercial Real Estate [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | Loan |  | 4
Pre-Modification Outstanding Recorded Investment |  | $ 439
Post Modification Oustanding Recorded Investment |  | $ 439
Residential Real Estate [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | Loan | 2 | 2
Pre-Modification Outstanding Recorded Investment | $ 155 | $ 195
Post Modification Oustanding Recorded Investment | $ 155 | $ 195

X
- Definition The number of loans relating to troubled debt restructurings. + References No definition available. + Details
Name: | cofs_NumberOfLoans
Namespace Prefix: | cofs_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Post-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Pre-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cofs_AgriculturalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |