FAIR VALUE OF FINANCIAL INSTRUMENTS, Measured On A Recurring And Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Recurring [Member]
Securities available for sale [Abstract]
U.S. agency securities	$ 170,414	$ 199,591
U.S. treasuries securities	3,000	10,082
Obligations of state and political subdivisions	96,926	102,863
Corporate obligations	3,050	14,565
Mortgage-backed securities in government sponsored entities	37,728	30,204
Equity securities in financial institutions	2,899	2,432
Recurring [Member] \| Level I [Member]
Securities available for sale [Abstract]
U.S. agency securities	0	0
U.S. treasuries securities	3,000	10,082
Obligations of state and political subdivisions	0	0
Corporate obligations	0	0
Mortgage-backed securities in government sponsored entities	0	0
Equity securities in financial institutions	2,899	2,432
Recurring [Member] \| Level II [Member]
Securities available for sale [Abstract]
U.S. agency securities	170,414	199,591
U.S. treasuries securities	0	0
Obligations of state and political subdivisions	96,926	102,863
Corporate obligations	3,050	14,565
Mortgage-backed securities in government sponsored entities	37,728	30,204
Equity securities in financial institutions	0	0
Recurring [Member] \| Level III [Member]
Securities available for sale [Abstract]
U.S. agency securities	0	0
U.S. treasuries securities	0	0
Obligations of state and political subdivisions	0	0
Corporate obligations	0	0
Mortgage-backed securities in government sponsored entities	0	0
Equity securities in financial institutions	0	0
Nonrecurring [Member]
Fair value assets and liabilities measured on non-recurring basis [Abstract]
Impaired Loans	2,033	894
Other real estate owned	839	1,197
Nonrecurring [Member] \| Level I [Member]
Fair value assets and liabilities measured on non-recurring basis [Abstract]
Impaired Loans	0	0
Other real estate owned	0	0
Nonrecurring [Member] \| Level II [Member]
Fair value assets and liabilities measured on non-recurring basis [Abstract]
Impaired Loans	0	0
Other real estate owned	0	0
Nonrecurring [Member] \| Level III [Member]
Fair value assets and liabilities measured on non-recurring basis [Abstract]
Impaired Loans	2,033	894
Other real estate owned	$ 839	$ 1,197

No definition available.

Name:	czfs_CorporateObligationsFairValueDisclosure
Namespace Prefix:	czfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

+ References

No definition available.

+ Details

Name:	czfs_EquitySecuritiesInFinancialInstitutionsFairValueDisclosure
Namespace Prefix:	czfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	czfs_FairValueAssetsAndLiabilitiesMeasuredOnNonrecurringBasisAbstract
Namespace Prefix:	czfs_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

+ References

No definition available.

+ Details

Name:	czfs_MortgageBackedSecuritiesInGovernmentSponsoredEntitiesFairValueDisclosure
Namespace Prefix:	czfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents bonds or similar securities issued by state, city, province, or local governments or their agencies in either the United States or a foreign country. Debt securities issued by state governments or provinces may include bond issuances of US state or foreign authorities. Debt securities issued by political subdivisions or US states may include debt issuances by county, borough, city, or municipal governments.

+ References

No definition available.

+ Details

Name:	czfs_ObligationsOfStateAndPoliticalSubdivisionsFairValueDisclosure
Namespace Prefix:	czfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

+ References

No definition available.

+ Details

Name:	czfs_USAgencySecuritiesFairValueDisclosure
Namespace Prefix:	czfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

+ References

No definition available.

+ Details

Name:	czfs_USTreasuriesSecuritiesFairValueDislosure
Namespace Prefix:	czfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Carrying amount as of the balance sheet date of all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings or defeasance; includes real and personal property; equity interests in corporations, partnerships, and joint ventures; and beneficial interests in trusts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4437-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5162-111524

+ Details

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

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: