XML 56 R47.htm IDEA: XBRL DOCUMENT v3.22.2

Note 8 - Derivative and Hedging Activities (Details Textual) $ in Billions	6 Months Ended
	Jun. 30, 2022 USD ($)
Pay Floating Swap Agreement [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative, Number of Instruments Held, Total	2
Derivative, Notional Amount	$ 0.2
Derivative, Fixed Coupon Rate	2.41%
Pay Fixed Swap Agreement [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative, Number of Instruments Held, Total	1
Derivative, Notional Amount	$ 0.2
Derivative, Fixed Coupon Rate	2.75%
Derivative, Term of Contract (Year)	8 years
Four SOFR Cap Agreements [Member]
Derivative, Number of Instruments Held, Total	4
Derivative, Notional Amount	$ 0.2
Derivative, Term of Contract (Year)	8 years
Three SOFR Cap Agreement [Member] | Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative, Notional Amount	$ 0.1
Derivative, Floor Interest Rate	2.68%
One SOFR Cap Agreement [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative, Notional Amount	$ 0.1
Derivative, Floor Interest Rate	2.68%

X

- Definition

Fixed coupon rate related to the derivative.

+ References

No definition available.

+ Details

Name:	cofs_DerivativeFixedCouponRate
Namespace Prefix:	cofs_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Floor rate on an interest rate derivative such as an interest rate floor or collar. If market rates falls below the floor rate, a payment or receipt is triggered on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFloorInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

+ Details

Name:	us-gaap_DerivativeNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

+ Details

Name:	us-gaap_DerivativeNumberOfInstrumentsHeld
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cofs_PayFloatingSwapAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cofs_PayFixedSwapAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cofs_FourSofrCapAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cofs_ThreeSofrCapAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_FairValueHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cofs_OneSofrCapAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: