XML 107 R97.htm IDEA: XBRL DOCUMENT
v3.22.2

Goodwill and Other Intangibles - Schedule of Changes in Intangible Liabilities (Details) $ in Millions | 6 Months Ended
--- | ---
Jun. 30, 2022 USD ($)
Finite-lived Intangible Liabilities [Roll Forward] |
Balance at January 1 | $ 0
Amortization | (8)
Balance at June 30, net of accumulated amortization | 44
CIT Group Inc. |
Finite-lived Intangible Liabilities [Roll Forward] |
Acquired in CIT Merger | $ 52

X
- Definition Amount of amortization of acquired leases acquired as part of a real property acquisition at below market lease rate with a finite life. + References No definition available. + Details
Name: | us-gaap_AmortizationOfBelowMarketLease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of acquired leases acquired as part of a real property acquisition at below market lease rate with a finite life. + References No definition available. + Details
Name: | us-gaap_BelowMarketLeaseAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount after amortization of leases acquired as part of a real property acquisition at below market lease rate with a finite life. + References No definition available. + Details
Name: | us-gaap_BelowMarketLeaseNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_BelowMarketLeaseRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=fcnca_CITGroupIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |