XML 132 R117.htm IDEA: XBRL DOCUMENT
v3.22.4

Variable Interest Entities - Narrative (Details) - entity | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Organization, Consolidation and Presentation of Financial Statements [Abstract] |  |
Variable interest entity, consolidated, number of entities | 0 | 0

X
- Definition Variable Interest Entity, Consolidated, Number Of Entities + References No definition available. + Details
Name: | fcnca_VariableInterestEntityConsolidatedNumberOfEntities
Namespace Prefix: | fcnca_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration