XML 40 R29.htm IDEA: XBRL DOCUMENT
v3.21.1

FDIC Shared-Loss Payable (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2021
FDIC Shared-Loss Receivable [Abstract] |
Changes In Payable to FDIC | The following table provides changes in the FDIC shared-loss payable since December 31, 2020:
(Dollars in thousands) | Total
Balance at December 31, 2020 | $ | 15,601 |
Accretion | 502 |
Payment made to the FDIC to settle shared-loss agreement | (16,103) |
Balance at March 31, 2021 | $ | — |

X
- Definition FDIC Shared-Loss Receivable [Abstract] + References No definition available. + Details
Name: | fcnca_FDICSharedLossReceivableAbstract
Namespace Prefix: | fcnca_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition [Table Text Block] for Schedule For FDIC Share-Loss Payable + References No definition available. + Details
Name: | fcnca_ScheduleForFDICShareLossPayableTableTextBlock
Namespace Prefix: | fcnca_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration