Name:	cizn_FinancingReceivableModificationsCollectionsDuringPeriod
Namespace Prefix:	cizn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Number of financing receivables that have been modified by troubled debt restructurings that are reclassified during the period

No definition available.

Name:	cizn_FinancingReceivableModificationsNumberOfContractsReclassified
Namespace Prefix:	cizn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of financing receivables that have been classified as troubled debt restructuring.

No definition available.

Name:	cizn_FinancingReceivableTroubledDebtRestructuringNumberOfContracts
Namespace Prefix:	cizn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Amount, after troubled debt restructuring, of modified financing receivable reclassified during the period.

No definition available.

Name:	cizn_FinancingReceivableTroubledDebtRestructuringReclassified
Namespace Prefix:	cizn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Number of financing receivables that have been modified by troubled debt restructurings.

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Amount, before troubled debt restructuring, of financing receivable to be modified.

Name:	us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of financing receivable modified as troubled debt restructuring.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554