XML 89 R73.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Allowance for Loan and Lease Losses (Troubled Debt Restructuring) (Details) $ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2018 USD ($) loans | Dec. 31, 2017 USD ($) loans | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($)
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | $ 156,130 | $ 164,561 |  |
Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | $ 214,568 | $ 211,867 | $ 205,026 | $ 189,904
Financing Receivable, Modifications, Number of Contracts | loans | 491 | 632 |  |
Nonaccruing | $ 84,546 | $ 92,534 |  |
Financing Receivable, Modifications, Recorded Investment | 137,910 | 146,126 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 43,553 | $ 49,000 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 164 | 204 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 13,318 | $ 11,990 |  |
PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | 9,144 | 10,026 | 13,769 | 16,312
Nonaccruing | 1,300 | 624 |  |
Financing Receivable, Modifications, Recorded Investment | 18,220 | 18,435 |  |
Commercial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 74,560 | 95,392 |  |
Commercial | Construction and land development |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 2,298 | 4,572 |  |
Commercial | Construction and land development | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | 35,270 | 24,470 | 28,877 | 16,288
Nonaccruing | 666 | 1,040 |  |
Commercial | Mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 61,065 | 78,221 |  |
Commercial | Mortgage | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | 43,451 | 45,005 | 48,278 | 69,896
Nonaccruing | 12,594 | 22,625 |  |
Commercial | Other commercial real estate |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 860 | 1,800 |  |
Commercial | Other commercial real estate | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | 2,481 | 4,571 | 3,269 | 2,168
Nonaccruing | 366 | 916 |  |
Commercial | Commercial and industrial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 10,046 | 10,278 |  |
Commercial | Commercial and industrial | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | 55,620 | 59,824 | 56,132 | 48,640
Nonaccruing | 4,624 | 4,876 |  |
Commercial | Other |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 291 | 521 |  |
Commercial | Other | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | 2,221 | 4,689 | 3,127 | 1,855
Noncommercial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 81,570 | 69,169 |  |
Noncommercial | Construction and land development |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 2,337 | 0 |  |
Noncommercial | Construction and land development | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | 2,350 | 3,962 | 1,596 | 1,485
Nonaccruing | 1,823 | 1,989 |  |
Noncommercial | Mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 47,524 | 43,542 |  |
Noncommercial | Mortgage | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | 15,472 | 15,706 | 14,447 | 14,105
Nonaccruing | 35,662 | 38,942 |  |
Noncommercial | Other | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 279 | 164 |  |
Noncommercial | Revolving mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 28,688 | 22,853 |  |
Noncommercial | Revolving mortgage | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Allowance for loan and lease losses | 21,862 | 22,436 | $ 21,013 | $ 15,971
Nonaccruing | 25,563 | 19,990 |  |
Noncommercial | Consumer and Other |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 3,021 | 2,774 |  |
Performing Financial Instruments [Member] |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 127,093 | 130,391 |  |
Performing Financial Instruments [Member] | Commercial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 64,171 | 76,300 |  |
Performing Financial Instruments [Member] | Commercial | Construction and land development |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 1,946 | 4,089 |  |
Performing Financial Instruments [Member] | Commercial | Mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 53,270 | 62,358 |  |
Performing Financial Instruments [Member] | Commercial | Other commercial real estate |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 851 | 1,012 |  |
Performing Financial Instruments [Member] | Commercial | Commercial and industrial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 7,986 | 8,320 |  |
Performing Financial Instruments [Member] | Commercial | Other |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 118 | 521 |  |
Performing Financial Instruments [Member] | Noncommercial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 62,922 | 54,091 |  |
Performing Financial Instruments [Member] | Noncommercial | Construction and land development |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 2,227 | 0 |  |
Performing Financial Instruments [Member] | Noncommercial | Mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 37,903 | 34,067 |  |
Performing Financial Instruments [Member] | Noncommercial | Revolving mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 20,492 | 17,673 |  |
Performing Financial Instruments [Member] | Noncommercial | Consumer and Other |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 2,300 | 2,351 |  |
Nonperforming Financial Instruments [Member] |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 29,037 | 34,170 |  |
Nonperforming Financial Instruments [Member] | Commercial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 10,389 | 19,092 |  |
Nonperforming Financial Instruments [Member] | Commercial | Construction and land development |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 352 | 483 |  |
Nonperforming Financial Instruments [Member] | Commercial | Mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 7,795 | 15,863 |  |
Nonperforming Financial Instruments [Member] | Commercial | Other commercial real estate |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 9 | 788 |  |
Nonperforming Financial Instruments [Member] | Commercial | Commercial and industrial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 2,060 | 1,958 |  |
Nonperforming Financial Instruments [Member] | Commercial | Other |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 173 | 0 |  |
Nonperforming Financial Instruments [Member] | Noncommercial |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 18,648 | 15,078 |  |
Nonperforming Financial Instruments [Member] | Noncommercial | Construction and land development |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 110 | 0 |  |
Nonperforming Financial Instruments [Member] | Noncommercial | Mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 9,621 | 9,475 |  |
Nonperforming Financial Instruments [Member] | Noncommercial | Revolving mortgage |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | 8,196 | 5,180 |  |
Nonperforming Financial Instruments [Member] | Noncommercial | Consumer and Other |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Nonaccruing | $ 721 | $ 423 |  |
Extended Maturity [Member] | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 42 | 47 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 5,486 | $ 6,517 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 8 | 2 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 865 | $ 273 |  |
Extended Maturity [Member] | Commercial | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 21 | 13 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 3,933 | $ 3,007 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 4 | 0 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 675 | $ 0 |  |
Extended Maturity [Member] | Noncommercial | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 21 | 34 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 1,554 | $ 3,510 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 4 | 2 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 190 | $ 273 |  |
Interest Rate Below Market Reduction [Member] | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 269 | 363 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 28,404 | $ 30,412 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 92 | 110 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 8,459 | $ 7,983 |  |
Interest Rate Below Market Reduction [Member] | Commercial | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 85 | 92 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 12,859 | $ 14,811 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 24 | 32 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 2,998 | $ 3,392 |  |
Interest Rate Below Market Reduction [Member] | Noncommercial | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 184 | 271 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 15,545 | $ 15,601 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 68 | 78 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 5,461 | $ 4,591 |  |
Discharge of Debt [Member] | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 177 | 216 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 8,660 | $ 10,865 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 64 | 91 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 3,994 | $ 3,100 |  |
Discharge of Debt [Member] | Commercial | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 26 | 39 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 2,043 | $ 3,012 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 8 | 26 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 825 | $ 708 |  |
Discharge of Debt [Member] | Noncommercial | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 151 | 177 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 6,617 | $ 7,853 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 56 | 65 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 3,169 | $ 2,392 |  |
Principal Forgiveness [Member] | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 3 | 6 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 1,003 | $ 1,206 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 0 | 1 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 0 | $ 634 |  |
Principal Forgiveness [Member] | Commercial | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 3 | 5 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 1,003 | $ 1,124 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 0 | 1 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 0 | $ 634 |  |
Principal Forgiveness [Member] | Noncommercial | Non-PCI Loans |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |
Financing Receivable, Modifications, Number of Contracts | loans | 0 | 1 |  |
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 0 | $ 82 |  |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | loans | 0 | 0 |  |
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $ 0 | $ 0 |  |

X
- Definition A valuation allowance for financing receivables that are expected to be uncollectible. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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_FinancingReceivableModificationsLineItems
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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Post-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | fcnca_LoanDesignationAxis=fcnca_NonPCILoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | fcnca_LoanDesignationAxis=us-gaap_FinancialAssetAcquiredWithCreditDeteriorationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_MortgageReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=fcnca_OtherRealEstateLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=fcnca_CommercialAndIndustrialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=fcnca_OtherLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fcnca_NoncommercialSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_HomeEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=fcnca_ConsumerAndOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_NonperformingFinancingReceivableMember
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=us-gaap_DischargeOfDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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