XML 92 R77.htm IDEA: XBRL DOCUMENT
v3.22.1

Loans and Leases - Schedule of Troubled Debt Restructuring Modifications (Details) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2022 USD ($) loan | Mar. 31, 2021 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Number of loans | loan | 81 | 129
Amortized cost at period end | $ | $ 24 | $ 23
Interest only |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Number of loans | loan | 2 | 6
Amortized cost at period end | $ | $ 0 | $ 7
Loan term extension |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Number of loans | loan | 35 | 25
Amortized cost at period end | $ | $ 20 | $ 4
Below market rates |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Number of loans | loan | 20 | 53
Amortized cost at period end | $ | $ 2 | $ 8
Discharge from bankruptcy |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Number of loans | loan | 24 | 45
Amortized cost at period end | $ | $ 2 | $ 4

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after troubled debt restructuring, of modified financing receivable. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_ContractualInterestRateReductionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_InterestRateBelowMarketReductionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=fcnca_DischargeFromBankruptcyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |