XML 63 R52.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Allowance for Loan and Lease Losses (Allocation of Allowance for Loan and Lease Losses) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | $ 161,971 |  | $ 161,971 |  | $ 164,561
Unpaid principal balance | 999,926 | $ 1,293,760 | 999,926 | $ 1,293,760 |
Loans and Leases Receivable, Net Amount | 24,667,150 |  | 24,667,150 |  | 23,374,932
Non-PCI impaired loans less than $500,000 collectively evaluated | 43,800 |  | 43,800 |  | 49,100
Commercial |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 81,451 |  | 81,451 |  | 95,392
Commercial | Construction and land development |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 2,350 |  | 2,350 |  | 4,572
Commercial | Mortgage |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 67,664 |  | 67,664 |  | 78,221
Commercial | Other commercial real estate |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 929 |  | 929 |  | 1,800
Commercial | Commercial and industrial |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 9,319 |  | 9,319 |  | 8,508
Commercial | Lease financing |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 947 |  | 947 |  | 1,770
Commercial | Other |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 242 |  | 242 |  | 521
Noncommercial |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 80,520 |  | 80,520 |  | 69,169
Noncommercial | Construction and land development |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 2,824 |  | 2,824 |  | 0
Noncommercial | Consumer and Other |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 2,887 |  | 2,887 |  | 2,774
Noncommercial | Mortgage |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 46,892 |  | 46,892 |  | 43,542
Noncommercial | Revolving mortgage |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 27,917 |  | 27,917 |  | 22,853
PCI Loans |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Financing Receivable, Modifications, Recorded Investment | 18,369 |  | 18,369 |  | 18,400
Acquired loans which have adverse change in expected cash flows | 190,800 |  | 190,800 |  | 279,800
Provision for Loan, Lease, and Other Losses | (1,514) | (537) | 1,000 | (810) |
Financing Receivable, Allowance for Credit Losses, Write-downs | 0 | 0 | 117 | 0 |
Recoveries | 0 | 0 | 0 | 0 |
Non-PCI Loans |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Total impaired noncovered loans and leases | 154,676 |  | 154,676 |  | 155,646
Unpaid principal balance | 174,111 |  | 174,111 |  | 170,034
Impaired Financing Receivable, Related Allowance | 11,425 |  | 11,425 |  | 9,728
ALLL for loans and leases individually evaluated for impairment | 11,425 |  | 11,425 |  | 9,728
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 116,919 |  | 116,919 |  | 77,199
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 37,757 |  | 37,757 |  | 78,447
Financing Receivable, Individually Evaluated for Impairment | 154,676 |  | 154,676 |  | 155,646
Average balance | 152,381 | 142,648 | 154,152 | 139,645 |
Interest income recognized | 1,350 | 1,225 | 4,092 | 3,552 |
Provision for Loan, Lease, and Other Losses | 2,354 | 8,483 | 15,883 | 29,311 |
Financing Receivable, Allowance for Credit Losses, Write-downs | 9,447 | 8,494 | 28,739 | 26,688 |
Recoveries | 2,939 | 3,592 | 9,277 | 11,234 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 196,863 |  | 196,863 |  | 202,139
Financing Receivable, Collectively Evaluated for Impairment | 24,093,653 |  | 24,093,653 |  | 22,678,181
Loans and Leases Receivable, Net Amount | 24,248,329 |  | 24,248,329 |  | 22,833,827
Non-PCI Loans | Commercial | Construction and land development |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 2,600 |  | 2,600 |  | 1,110
ALLL for loans and leases individually evaluated for impairment | 296 |  | 296 |  | 185
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 2,175 |  | 2,175 |  | 788
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 0 |  | 0 |  | 0
Financing Receivable, Individually Evaluated for Impairment | 2,175 |  | 2,175 |  | 788
Average balance | 2,101 | 754 | 1,580 | 926 |
Interest income recognized | 27 | 8 | 55 | 31 |
Provision for Loan, Lease, and Other Losses | 8,702 | (5,150) | 7,788 | (242) |
Financing Receivable, Allowance for Credit Losses, Write-downs | 35 | 9 | 43 | 499 |
Recoveries | 136 | 56 | 252 | 320 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 32,171 |  | 32,171 |  | 24,285
Financing Receivable, Collectively Evaluated for Impairment | 677,028 |  | 677,028 |  | 668,427
Loans and Leases Receivable, Net Amount | 679,203 |  | 679,203 |  | 669,215
Non-PCI Loans | Commercial | Mortgage |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 70,501 |  | 70,501 |  | 78,936
ALLL for loans and leases individually evaluated for impairment | 2,983 |  | 2,983 |  | 3,648
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 34,860 |  | 34,860 |  | 39,135
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 28,552 |  | 28,552 |  | 34,520
Financing Receivable, Individually Evaluated for Impairment | 63,412 |  | 63,412 |  | 73,655
Average balance | 63,752 | 73,099 | 68,043 | 74,177 |
Interest income recognized | 583 | 653 | 1,953 | 1,946 |
Provision for Loan, Lease, and Other Losses | (2,870) | (71) | (3,369) | 574 |
Financing Receivable, Allowance for Credit Losses, Write-downs | 606 | 39 | 1,111 | 311 |
Recoveries | 99 | 1,446 | 563 | 2,541 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 38,105 |  | 38,105 |  | 41,357
Financing Receivable, Collectively Evaluated for Impairment | 10,422,960 |  | 10,422,960 |  | 9,655,367
Loans and Leases Receivable, Net Amount | 10,486,372 |  | 10,486,372 |  | 9,729,022
Non-PCI Loans | Commercial | Other commercial real estate |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 1,104 |  | 1,104 |  | 2,267
ALLL for loans and leases individually evaluated for impairment | 46 |  | 46 |  | 209
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 199 |  | 199 |  | 1,351
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 730 |  | 730 |  | 506
Financing Receivable, Individually Evaluated for Impairment | 929 |  | 929 |  | 1,857
Average balance | 950 | 1,720 | 1,336 | 1,610 |
Interest income recognized | 10 | 8 | 33 | 25 |
Provision for Loan, Lease, and Other Losses | (1,219) | 891 | (2,044) | 1,228 |
Financing Receivable, Allowance for Credit Losses, Write-downs | 0 | 0 | 69 | 5 |
Recoveries | 1 | 8 | 147 | 19 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 2,559 |  | 2,559 |  | 4,362
Financing Receivable, Collectively Evaluated for Impairment | 470,603 |  | 470,603 |  | 471,576
Loans and Leases Receivable, Net Amount | 471,532 |  | 471,532 |  | 473,433
Non-PCI Loans | Commercial | Commercial and industrial |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 14,050 |  | 14,050 |  | 10,475
ALLL for loans and leases individually evaluated for impairment | 1,133 |  | 1,133 |  | 665
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 6,573 |  | 6,573 |  | 6,326
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 2,475 |  | 2,475 |  | 1,648
Financing Receivable, Individually Evaluated for Impairment | 9,048 |  | 9,048 |  | 7,974
Average balance | 8,278 | 9,501 | 7,796 | 10,396 |
Interest income recognized | 83 | 96 | 235 | 298 |
Provision for Loan, Lease, and Other Losses | (9,271) | 5,621 | (4,026) | 10,181 |
Financing Receivable, Allowance for Credit Losses, Write-downs | 1,256 | 1,275 | 4,725 | 7,649 |
Recoveries | 494 | 433 | 2,351 | 3,090 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 46,164 |  | 46,164 |  | 53,032
Financing Receivable, Collectively Evaluated for Impairment | 3,180,289 |  | 3,180,289 |  | 2,722,433
Loans and Leases Receivable, Net Amount | 3,189,337 |  | 3,189,337 |  | 2,730,407
Non-PCI Loans | Commercial | Lease financing |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 1,894 |  | 1,894 |  | 2,571
ALLL for loans and leases individually evaluated for impairment | 135 |  | 135 |  | 397
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 755 |  | 755 |  | 1,890
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 287 |  | 287 |  | 24
Financing Receivable, Individually Evaluated for Impairment | 1,042 |  | 1,042 |  | 1,914
Average balance | 1,032 | 1,752 | 1,704 | 1,744 |
Interest income recognized | 9 | 12 | 34 | 40 |
Provision for Loan, Lease, and Other Losses | 4,011 | 884 | 3,119 | 1,645 |
Financing Receivable, Allowance for Credit Losses, Write-downs | 850 | 687 | 2,149 | 957 |
Recoveries | 3 | 3 | 48 | 9 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 7,010 |  | 7,010 |  | 5,730
Financing Receivable, Collectively Evaluated for Impairment | 615,909 |  | 615,909 |  | 892,887
Loans and Leases Receivable, Net Amount | 616,951 |  | 616,951 |  | 894,801
Non-PCI Loans | Commercial | Other |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 246 |  | 246 |  | 521
ALLL for loans and leases individually evaluated for impairment | 18 |  | 18 |  | 0
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 241 |  | 241 |  | 0
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 0 |  | 0 |  | 521
Financing Receivable, Individually Evaluated for Impairment | 241 |  | 241 |  | 521
Average balance | 205 | 557 | 90 | 396 |
Interest income recognized | 1 | 8 | 1 | 15 |
Provision for Loan, Lease, and Other Losses | (2,404) | 58 | (2,403) | 299 |
Financing Receivable, Allowance for Credit Losses, Write-downs | 56 | 666 | 98 | 853 |
Recoveries | 117 | 123 | 160 | 244 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 2,330 |  | 2,330 |  | 4,689
Financing Receivable, Collectively Evaluated for Impairment | 296,747 |  | 296,747 |  | 301,655
Loans and Leases Receivable, Net Amount | 296,988 |  | 296,988 |  | 302,176
Non-PCI Loans | Noncommercial | Construction and land development |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 4,527 |  | 4,527 |  | 5,224
ALLL for loans and leases individually evaluated for impairment | 501 |  | 501 |  | 68
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 4,236 |  | 4,236 |  | 592
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 0 |  | 0 |  | 3,959
Financing Receivable, Individually Evaluated for Impairment | 4,236 |  | 4,236 |  | 4,551
Average balance | 3,190 | 3,676 | 3,607 | 3,155 |
Interest income recognized | 42 | 35 | 134 | 101 |
Provision for Loan, Lease, and Other Losses | (1,203) | 92 | (1,046) | (1) |
Financing Receivable, Allowance for Credit Losses, Write-downs | 0 | 0 | 219 | 0 |
Recoveries | 0 | 0 | 127 | 0 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 2,323 |  | 2,323 |  | 3,894
Financing Receivable, Collectively Evaluated for Impairment | 237,200 |  | 237,200 |  | 243,738
Loans and Leases Receivable, Net Amount | 241,436 |  | 241,436 |  | 248,289
Non-PCI Loans | Noncommercial | Mortgage |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 45,528 |  | 45,528 |  | 39,946
ALLL for loans and leases individually evaluated for impairment | 2,791 |  | 2,791 |  | 2,733
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 40,128 |  | 40,128 |  | 19,135
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 2,489 |  | 2,489 |  | 18,707
Financing Receivable, Individually Evaluated for Impairment | 42,617 |  | 42,617 |  | 37,842
Average balance | 42,601 | 31,290 | 41,124 | 33,673 |
Interest income recognized | 330 | 228 | 903 | 753 |
Provision for Loan, Lease, and Other Losses | (1,828) | 531 | 1,176 | 2,037 |
Financing Receivable, Allowance for Credit Losses, Write-downs | 360 | 604 | 1,455 | 1,076 |
Recoveries | 128 | 92 | 315 | 454 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 12,951 |  | 12,951 |  | 12,973
Financing Receivable, Collectively Evaluated for Impairment | 4,030,618 |  | 4,030,618 |  | 3,485,944
Loans and Leases Receivable, Net Amount | 4,073,235 |  | 4,073,235 |  | 3,523,786
Non-PCI Loans | Noncommercial | Revolving mortgage |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 30,463 |  | 30,463 |  | 25,941
ALLL for loans and leases individually evaluated for impairment | 2,759 |  | 2,759 |  | 1,085
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 24,953 |  | 24,953 |  | 5,875
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 3,136 |  | 3,136 |  | 17,895
Financing Receivable, Individually Evaluated for Impairment | 28,089 |  | 28,089 |  | 23,770
Average balance | 27,503 | 18,066 | 26,228 | 11,506 |
Interest income recognized | 234 | 150 | 657 | 269 |
Provision for Loan, Lease, and Other Losses | 465 | 842 | 1,220 | 2,446 |
Financing Receivable, Allowance for Credit Losses, Write-downs | 759 | 218 | 2,778 | 1,323 |
Recoveries | 712 | 228 | 1,426 | 1,181 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 19,545 |  | 19,545 |  | 21,351
Financing Receivable, Collectively Evaluated for Impairment | 2,542,007 |  | 2,542,007 |  | 2,677,755
Loans and Leases Receivable, Net Amount | 2,570,096 |  | 2,570,096 |  | 2,701,525
Non-PCI Loans | Noncommercial | Consumer |  |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |  |
Unpaid principal balance | 3,198 |  | 3,198 |  | 3,043
ALLL for loans and leases individually evaluated for impairment | 763 |  | 763 |  | 738
Impaired Financing Receivable, with Related Allowance, Recorded Investment | 2,799 |  | 2,799 |  | 2,107
Impaired Financing Receivable, with No Related Allowance, Recorded Investment | 88 |  | 88 |  | 667
Financing Receivable, Individually Evaluated for Impairment | 2,887 |  | 2,887 |  | 2,774
Average balance | 2,769 | 2,233 | 2,644 | 2,062 |
Interest income recognized | 31 | 27 | 87 | 74 |
Provision for Loan, Lease, and Other Losses | 7,971 | 4,785 | 15,468 | 11,144 |
Financing Receivable, Allowance for Credit Losses, Write-downs | 5,525 | 4,996 | 16,092 | 14,015 |
Recoveries | 1,249 | $ 1,203 | 3,888 | $ 3,376 |
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment | 33,705 |  | 33,705 |  | 30,466
Financing Receivable, Collectively Evaluated for Impairment | 1,620,292 |  | 1,620,292 |  | 1,558,399
Loans and Leases Receivable, Net Amount | $ 1,623,179 |  | $ 1,623,179 |  | $ 1,561,173

X
- Definition Acquired Loans Which Have Adverse Change In Expected Cash Flows + References No definition available. + Details
Name: | fcnca_AcquiredLoansWhichHaveAdverseChangeInExpectedCashFlows
Namespace Prefix: | fcnca_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The recorded investment of impaired financing receivables less than $500,000 that are collectively evaluated. + References No definition available. + Details
Name: | fcnca_ImpairedFinancingReceivableCollectivelyEvaluated
Namespace Prefix: | fcnca_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment. + 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 (g) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment. + 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 (g) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
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_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of recovery of financing receivables doubtful of collection that were previously charged off. + 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)(4) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of direct write-downs of financing receivables charged against the allowance. + 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)(3) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The balance of financing receivables that were collectively evaluated for impairment. + 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 (h) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The balance of financing receivables that were individually evaluated for impairment. + 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 (h) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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 Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of allowance for credit losses related to recorded investment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableRelatedAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in impaired financing receivables for which there is no related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in impaired financing receivables for which there is a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_LoansAndLeasesReceivableNetReportedAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value. + 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)(2) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.11) -URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
Name: | us-gaap_ProvisionForLoanLeaseAndOtherLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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=us-gaap_FinanceLeasesPortfolioSegmentMember
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=fcnca_ConsumerAndOtherMember
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: | fcnca_LoanDesignationAxis=us-gaap_FinancialAssetAcquiredWithCreditDeteriorationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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