Subordinated Debentures - Schedule of Subordinated Debentures (Parenthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Subordinated Note [Member]
Subordinated Borrowing [Line Items]
Basis spread on variable rate	2.19%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Debt instrument, variable interest rate percentage	3.25%	3.25%
Net of unamortized debt issuance costs	$ 1,260	$ 1,406
Subordinated Note [Member] \| December 31, 2031 [Member]
Subordinated Borrowing [Line Items]
Maturities of subordinated debt	$ 75,000
First Citizens Statutory Trust II [Member]
Subordinated Borrowing [Line Items]
Basis spread on variable rate	3.15%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Debt instrument, variable interest rate percentage	8.07%	8.81%
First Citizens Statutory Trust II [Member] \| March 26, 2033 [Member]
Subordinated Borrowing [Line Items]
Maturities of subordinated debt	$ 7,732
First Citizens Statutory Trust III [Member]
Subordinated Borrowing [Line Items]
Basis spread on variable rate	2.25%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Debt instrument, variable interest rate percentage	7.32%	7.91%
First Citizens Statutory Trust III [Member] \| September 20, 2034 [Member]
Subordinated Borrowing [Line Items]
Maturities of subordinated debt	$ 12,887
First Citizens Statutory Trust IV [Member]
Subordinated Borrowing [Line Items]
Basis spread on variable rate	1.60%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Debt instrument, variable interest rate percentage	6.81%	7.27%
First Citizens Statutory Trust IV [Member] \| March 23, 2037 [Member]
Subordinated Borrowing [Line Items]
Maturities of subordinated debt	$ 5,155
Futura TPF Trust I [Member]
Subordinated Borrowing [Line Items]
Basis spread on variable rate	1.66%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Debt instrument, variable interest rate percentage	6.87%	7.33%
Futura TPF Trust I [Member] \| June 15, 2035 [Member]
Subordinated Borrowing [Line Items]
Maturities of subordinated debt	$ 2,578
Futura TPF Trust II [Member]
Subordinated Borrowing [Line Items]
Basis spread on variable rate	1.66%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member]
Debt instrument, variable interest rate percentage	6.87%	7.33%
Net of purchase discount	$ 73
Futura TPF Trust II [Member] \| June 15, 2035 [Member]
Subordinated Borrowing [Line Items]
Maturities of subordinated debt	$ 2,070

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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- Definition

Amount, after accumulated amortization, of debt discount (premium).

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- Definition

Indicates type of variable interest rate on debt instrument.

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- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

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- Definition

The cash outflow for a long-term borrowing where lender is placed in a lien position behind debt having a higher priority of repayment (senior) in case of liquidation of the entity's assets as it matures.

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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.

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