XML 41 R35.htm IDEA: XBRL DOCUMENT v3.24.3

Securities - Schedule of Maturities of Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt and Equity Securities, FV-NI [Line Items]
Less than 1 Year	$ 9,711
1 Year - 5 Years	176,676
5 Years - 10 Years	199,549
More than 10 Years	111,616
Fair value, available for sale	497,552	$ 514,598
Total Available for Sale	497,552
Held to Maturity Securities maturing within Less than 1 Year	16,520
Held to Maturity Securities maturing within 1 Year -5 Years	59,783
Held to Maturity Securities maturing within 5 Years -10 Years	240,513
Held to Maturity Securities maturing within More than10 Years	75,138
Held to Maturity Securities maturing within amortized cost	391,954
U.S. Government and Federal Agency [Member]
Debt and Equity Securities, FV-NI [Line Items]
Held to Maturity Securities maturing within Less than 1 Year	0
Held to Maturity Securities maturing within 1 Year -5 Years	2,977
Held to Maturity Securities maturing within 5 Years -10 Years	0
Held to Maturity Securities maturing within More than10 Years	0
Held to Maturity Securities maturing within amortized cost	2,977
U.S. Treasury Notes and Bonds [Member]
Debt and Equity Securities, FV-NI [Line Items]
Less than 1 Year	0
1 Year - 5 Years	82,232
5 Years - 10 Years	0
More than 10 Years	0
Fair value, available for sale	82,232	80,194
State and Municipal [Member]
Debt and Equity Securities, FV-NI [Line Items]
Less than 1 Year	1,018
1 Year - 5 Years	22,377
5 Years - 10 Years	113,176
More than 10 Years	98,463
Fair value, available for sale	235,034	234,682
Held to Maturity Securities maturing within Less than 1 Year	2,972
Held to Maturity Securities maturing within 1 Year -5 Years	19,729
Held to Maturity Securities maturing within 5 Years -10 Years	98,326
Held to Maturity Securities maturing within More than10 Years	75,138
Held to Maturity Securities maturing within amortized cost	196,165
Corporate [Member]
Debt and Equity Securities, FV-NI [Line Items]
Less than 1 Year	0
1 Year - 5 Years	0
5 Years - 10 Years	213
More than 10 Years	0
Fair value, available for sale	213	204
Held to Maturity Securities maturing within Less than 1 Year	0
Held to Maturity Securities maturing within 1 Year -5 Years	0
Held to Maturity Securities maturing within 5 Years -10 Years	20,036
Held to Maturity Securities maturing within More than10 Years	0
Held to Maturity Securities maturing within amortized cost	20,036
Asset-backed Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Less than 1 Year	0
1 Year - 5 Years	6,793
5 Years - 10 Years	2,521
More than 10 Years	0
Fair value, available for sale	9,314	11,017
Held to Maturity Securities maturing within Less than 1 Year	300
Held to Maturity Securities maturing within 1 Year -5 Years	0
Held to Maturity Securities maturing within 5 Years -10 Years	0
Held to Maturity Securities maturing within More than10 Years	0
Held to Maturity Securities maturing within amortized cost	300
Total debt securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Less than 1 Year	1,018
1 Year - 5 Years	111,402
5 Years - 10 Years	115,910
More than 10 Years	98,463
Fair value, available for sale	326,793
Held to Maturity Securities maturing within Less than 1 Year	3,272
Held to Maturity Securities maturing within 1 Year -5 Years	22,706
Held to Maturity Securities maturing within 5 Years -10 Years	118,362
Held to Maturity Securities maturing within More than10 Years	75,138
Held to Maturity Securities maturing within amortized cost	219,478
Mortgage-backed [Member]
Debt and Equity Securities, FV-NI [Line Items]
Less than 1 Year	8,693
1 Year - 5 Years	65,274
5 Years - 10 Years	83,639
More than 10 Years	13,153
Fair value, available for sale	170,759	$ 188,501
Held to Maturity Securities maturing within Less than 1 Year	13,248
Held to Maturity Securities maturing within 1 Year -5 Years	37,077
Held to Maturity Securities maturing within 5 Years -10 Years	122,151
Held to Maturity Securities maturing within More than10 Years	0
Held to Maturity Securities maturing within amortized cost	$ 172,476

X

- Definition

Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), and equity security measured at fair value with change in fair value recognized in net income (FV-NI), with single maturity date and allocated without single maturity date, maturing after rolling tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

+ References

No definition available.

+ Details

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

X

- Definition

Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), maturing in rolling sixth through tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

+ References

No definition available.

+ Details

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

X

- Definition

Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), maturing in rolling second through fifth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

+ References

No definition available.

+ Details

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

X

- Definition

Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), maturing in next rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

+ References

No definition available.

+ Details

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

X

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 103
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-103

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aa)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481830/320-10-45-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

+ Details

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

X

- Definition

Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 320
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477268/942-320-50-3

+ Details

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

X

- Definition

Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year following current statement of financial position date. For interim and annual periods when interim period is reported on rolling approach.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 320
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477268/942-320-50-3

+ Details

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

X

- Definition

Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing after rolling tenth fiscal year following current statement of financial position date. For interim and annual periods when interim period is reported on rolling approach.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 320
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477268/942-320-50-3

+ Details

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

X

- Definition

Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing in sixth through tenth rolling fiscal year following current statement of financial position date. For interim and annual periods when interim period is reported on rolling approach.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 320
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477268/942-320-50-3

+ Details

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

X

- Definition

Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing in second through fifth rolling fiscal year following current statement of financial position date. For interim and annual periods when interim period is reported on rolling approach.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 320
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477268/942-320-50-3

+ Details

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

X

- Definition

Sum of the carrying amounts as of the balance sheet date of all investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480078/944-80-55-14

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480078/944-80-55-9

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(h))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

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

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6B

+ Details

Name:	us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: