XML 58 R48.htm IDEA: XBRL DOCUMENT v3.20.2

Note 8 - Business Combination (Details Textual)			3 Months Ended	9 Months Ended
	Jul. 01, 2020 USD ($) shares	Oct. 01, 2019 USD ($) shares	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Stock Issued During Period, Value, Acquisitions			$ 15,494,000	$ 15,494,000
County Bank Corp ("County") [Member]
Number of Branch Offices		14
Number of Loan Office		1
Community Shores Bank Corp ("Community Shores") [Member]
Number of Branch Offices	4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total	$ 243,975,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Total Loans	174,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Total Deposits	$ 227,832,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares) | shares	524,139
Business Acquisition, Equity Interest Issued or Issuable, Number of Fractional Shares (in shares) | shares	84
Payments to Acquire Businesses, Gross	$ 5,390,000
Business Combination, Consideration Transferred, Total	$ 20,881,000
County Bank Corp ("County") [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total		$ 672,762,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Total Loans		424,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Total Deposits		573,601,000
Business Combination, Consideration Transferred, Total		$ 107,945,000
County Bank Corp ("County") [Member] | Common Stock [Member]
Stock Issued During Period, Shares, Acquisitions (in shares) | shares		3,603,872
Stock Issued During Period, Value, Acquisitions		$ 108,000,000
County Bank Corp ("County") [Member] | Fractional Stock [Member]
Stock Issued During Period, Shares, Acquisitions (in shares) | shares		299

X

- Definition

Number of fractional shares of equity interests issued or issuable to acquire entity.

+ References

No definition available.

+ Details

Name:	cofs_BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfFractionalShares
Namespace Prefix:	cofs_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of liability arising from total deposits.

+ References

No definition available.

+ Details

Name:	cofs_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedTotalDeposits
Namespace Prefix:	cofs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Represents total loans for business combination recognized identifiable assets acquired and liabilities.

+ References

No definition available.

+ Details

Name:	cofs_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedTotalLoans
Namespace Prefix:	cofs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Represents number of branch office.

+ References

No definition available.

+ Details

Name:	cofs_NumberOfBranchOffices
Namespace Prefix:	cofs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Represents information related to number of loan office.

+ References

No definition available.

+ Details

Name:	cofs_NumberOfLoanOffice
Namespace Prefix:	cofs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of shares of equity interests issued or issuable to acquire entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479

+ Details

Name:	us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6613-128477

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of assets acquired at the acquisition date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121647850&loc=d3e4845-128472

+ Details

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Number of shares of stock issued during the period pursuant to acquisitions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesAcquisitions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Value of stock issued pursuant to acquisitions during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockIssuedDuringPeriodValueAcquisitions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	dei_LegalEntityAxis=cofs_CountyBankCorpCountyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=cofs_CommunityShoresBankCorpCommunityShoresMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=cofs_CountyBankCorpCountyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementEquityComponentsAxis=cofs_FractionalStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: