Business Combination, Number Of Retirement Plans Assumed

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Deferred Compensation Arrangement With Individual, Calculation Of Postretirement Benefits, Number Of Consecutive Years

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Deferred Compensation Arrangement With Individual, Calculation Of Postretirement Benefits, Term

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Defined Contribution Plan, Employer Non-Elective Contribution, Vesting Period

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Number of Defined Benefit Pension Plans

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Maximum term of the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Minimum period the individual is required to perform services to be fully vested under the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level.

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Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

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Weighted-average interest crediting rate used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, cash balance and other defined benefit plans with promised interest crediting rate.

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- Definition

Amount of contribution received by defined benefit plan from employer which increases plan assets.

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Amount of increase (decrease) in benefit obligation of defined benefit plan from change in terms of existing plan or initiation of new plan.

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Amount of cost for defined contribution plan.

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Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

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Percentage employer matches of the employee's percentage contribution matched.

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Amount of the liabilities for deferred compensation arrangements classified as other.

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Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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.

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Employee Benefit Plans - Narrative (Details) $ in Thousands	3 Months Ended	12 Months Ended
Employee Benefit Plans - Narrative (Details) $ in Thousands	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($) defined_benefit_plan	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jan. 03, 2022 retirement_plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of defined benefit pension plans \| defined_benefit_plan		3
Interest crediting rate		1.50%
Pension assets		$ 343,000	$ 289,000
Pension liabilities		54,000
Defined benefit plan, accumulated benefit obligation		1,100,000	973,000
Defined contribution plan, cost		$ 55,000	36,000	$ 36,000
Deferred compensation arrangement with individual, maximum contractual term		10 years
Other compensation plan, accrued liability		$ 267,000	84,000
Postretirement Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of retirement plans assumed \| retirement_plan					4
Defined benefit plan, benefit obligation, increase (decrease) for plan amendment	$ (27,000)
BancShares Pension Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employer contributions		$ 0	32
Vesting period		5 years
Number of consecutive years		5 years
Calculation of postretirement benefits, term		10 years
Bancorporation Pension Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employer contributions		$ 0	$ 0
Vesting period		5 years
Number of consecutive years		5 years
Calculation of postretirement benefits, term		10 years
CIT Pension Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employer contributions		$ 0
Supplemental and Executive Retirement Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employer contributions		$ 0
Interest crediting rate		1.90%
401(k) Contribution Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay		4.50%
Enhanced 401(K) Savings Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, employer matching contribution, percent of match		100.00%
Defined contribution plan, employer non-elective contribution, vesting period		3 years
Enhanced 401(K) Savings Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay		6.00%
CIT 401(k) Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, employer matching contribution, percent of match		100.00%
CIT 401(k) Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay		4.00%
Defined Contribution Plan, Employer Matching Contribution, First Portion \| 401(k) Contribution Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, employer matching contribution, percent of match		100.00%
Defined contribution plan, employer matching contribution, percent of employees' gross pay		3.00%
Defined Contribution Plan, Employer Matching Contribution, Next Portion \| 401(k) Contribution Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, employer matching contribution, percent of match		50.00%
Defined contribution plan, employer matching contribution, percent of employees' gross pay		3.00%
Defined Contribution Plan, Employer Matching Contribution, Minimum Contribution \| Enhanced 401(K) Savings Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined contribution plan, employer matching contribution, percent of employees' gross pay		3.00%
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs vesting period		3 years
RSUs vested and settled in period, fair value		$ 64,000