XML 135 R125.htm IDEA: XBRL DOCUMENT
v3.23.3

Business Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2022
Segment Reporting Information [Line Items] |  |  |  |  |
Net interest income (expense) | $ 1,990 | $ 795 | $ 4,801 | $ 2,144 |
(Benefit) provision for credit losses | 192 | 60 | 1,126 | 566 |
Net interest income after provision for credit losses | 1,798 | 735 | 3,675 | 1,578 |
Noninterest income | 615 | 433 | 11,532 | 1,707 |
Noninterest expense | 1,416 | 760 | 3,843 | 2,315 |
Income (loss) before income taxes | 997 | 408 | 11,364 | 970 |
Income tax expense (benefit) | 245 | 93 | 412 | 129 |
Net income | 752 | 315 | 10,952 | 841 |
Loans and leases | 133,202 | 69,790 | 133,202 | 69,790 | $ 70,781
Deposits | 146,233 | 87,553 | 146,233 | 87,553 | 89,408
Operating lease equipment, net | 8,661 | 7,984 | 8,661 | 7,984 | $ 8,156
Operating Segments | General Banking |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
Net interest income (expense) | 625 | 495 | 1,790 | 1,400 |
(Benefit) provision for credit losses | 7 | 2 | 48 | (7) |
Net interest income after provision for credit losses | 618 | 493 | 1,742 | 1,407 |
Noninterest income | 125 | 118 | 362 | 371 |
Noninterest expense | 411 | 400 | 1,192 | 1,192 |
Income (loss) before income taxes | 332 | 211 | 912 | 586 |
Income tax expense (benefit) | 91 | 55 | 228 | 143 |
Net income | 241 | 156 | 684 | 443 |
Loans and leases | 46,077 | 41,693 | 46,077 | 41,693 |
Deposits | 101,021 | 82,731 | 101,021 | 82,731 |
Operating lease equipment, net | 0 | 0 | 0 | 0 |
Operating Segments | Commercial Banking |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
Net interest income (expense) | 249 | 230 | 744 | 641 |
(Benefit) provision for credit losses | 132 | 58 | 353 | 60 |
Net interest income after provision for credit losses | 117 | 172 | 391 | 581 |
Noninterest income | 139 | 133 | 420 | 376 |
Noninterest expense | 205 | 186 | 615 | 555 |
Income (loss) before income taxes | 51 | 119 | 196 | 402 |
Income tax expense (benefit) | 14 | 24 | 55 | 90 |
Net income | 37 | 95 | 141 | 312 |
Loans and leases | 30,220 | 28,023 | 30,220 | 28,023 |
Deposits | 3,370 | 3,682 | 3,370 | 3,682 |
Operating lease equipment, net | 739 | 736 | 739 | 736 |
Operating Segments | Silicon Valley Banking |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
Net interest income (expense) | 635 | 0 | 1,335 | 0 |
(Benefit) provision for credit losses | 56 | 0 | 9 | 0 |
Net interest income after provision for credit losses | 579 | 0 | 1,326 | 0 |
Noninterest income | 151 | 0 | 334 | 0 |
Noninterest expense | 514 | 0 | 1,139 | 0 |
Income (loss) before income taxes | 216 | 0 | 521 | 0 |
Income tax expense (benefit) | 59 | 0 | 140 | 0 |
Net income | 157 | 0 | 381 | 0 |
Loans and leases | 56,864 | 0 | 56,864 | 0 |
Deposits | 39,970 | 0 | 39,970 | 0 |
Operating lease equipment, net | 0 | 0 | 0 | 0 |
Operating Segments | Rail |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
Net interest income (expense) | (40) | (20) | (101) | (58) |
(Benefit) provision for credit losses | 0 | 0 | 0 | 0 |
Net interest income after provision for credit losses | (40) | (20) | (101) | (58) |
Noninterest income | 194 | 170 | 549 | 493 |
Noninterest expense | 116 | 110 | 357 | 320 |
Income (loss) before income taxes | 38 | 40 | 91 | 115 |
Income tax expense (benefit) | 10 | 10 | 23 | 28 |
Net income | 28 | 30 | 68 | 87 |
Loans and leases | 41 | 74 | 41 | 74 |
Deposits | 12 | 14 | 12 | 14 |
Operating lease equipment, net | 7,922 | 7,248 | 7,922 | 7,248 |
Corporate |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
Net interest income (expense) | 521 | 90 | 1,033 | 161 |
(Benefit) provision for credit losses | (3) | 0 | 716 | 513 |
Net interest income after provision for credit losses | 524 | 90 | 317 | (352) |
Noninterest income | 6 | 12 | 9,867 | 467 |
Noninterest expense | 170 | 64 | 540 | 248 |
Income (loss) before income taxes | 360 | 38 | 9,644 | (133) |
Income tax expense (benefit) | 71 | 4 | (34) | (132) |
Net income | 289 | 34 | 9,678 | (1) |
Loans and leases | 0 | 0 | 0 | 0 |
Deposits | 1,860 | 1,126 | 1,860 | 1,126 |
Operating lease equipment, net | $ 0 | $ 0 | $ 0 | $ 0 |

X
- Definition Credit Loss Expense (Reversal) + References No definition available. + Details
Name: | fcnca_CreditLossExpenseReversal
Namespace Prefix: | fcnca_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Interest Income (Expense), after Provision for Credit Loss + References No definition available. + Details
Name: | fcnca_InterestIncomeExpenseAfterProvisionForCreditLoss
Namespace Prefix: | fcnca_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.12) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 + Details
Name: | us-gaap_Deposits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-3B Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-5 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(11)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 30 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-30 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 31 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-31 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-05(b)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479557/942-235-S99-1 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 25 -Paragraph 1 -SubTopic 20 -Topic 940 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481913/940-20-25-1 Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(10)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(15)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 + Details
Name: | us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-9 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-10 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I.7) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (h) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(9)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Subparagraph (a) -SubTopic 20 -Topic 740 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482659/740-20-45-2 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)) -SubTopic 10 -Topic 235 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1 + Details
Name: | us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The net amount of operating interest income (expense). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.10) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 + Details
Name: | us-gaap_InterestIncomeExpenseNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481687/323-10-50-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482907/825-10-50-28 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482765/220-10-50-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-3 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-1 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 65 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480175/815-40-65-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-8 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-9 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-11 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-11 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 250 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483443/250-10-50-4 Reference 13: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480167/946-830-55-10 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section 45 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483581/946-220-45-7 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-22 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(9)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(1)(d)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 20: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B Reference 29: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 30 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-30 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 31: http://www.xbrl.org/2003/role/disclosureRef -Topic 260 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 60B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482689/260-10-45-60B Reference 32: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 31 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-31 Reference 33: http://www.xbrl.org/2003/role/disclosureRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482810/280-10-50-32 Reference 34: http://www.xbrl.org/2003/role/disclosureRef -Topic 205 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483499/205-20-50-7 Reference 35: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-28 Reference 36: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482790/220-10-45-1A Reference 37: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B Reference 38: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(20)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2 Reference 39: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total aggregate amount of all noninterest expense. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.14) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 + Details
Name: | us-gaap_NoninterestExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.13) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1 + Details
Name: | us-gaap_NoninterestIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, after accumulated depreciation, of lessor's underlying asset for which right to use has been conveyed to lessee under operating lease. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 840 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481501/840-20-50-4 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 842 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479773/842-30-50-13 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 360 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482099/360-10-50-1 + Details
Name: | us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=fcnca_GeneralBankingSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=fcnca_CommercialBankingSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=fcnca_SiliconValleyBridgeBankSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=fcnca_RailSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_CorporateNonSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |