Amount transferred from loans held for investment net of unearned interest to loans held for sale.

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Collateral dependent loans financing receivable with related allowance interest income accrual method.

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Financing receivable modifications due to impact of CARES act.

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Nonaccrual loan amount guaranteed by government agencies.

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Paycheck protection program amortized processing fees recognized as interest income.

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Percentage of loans secured by real estate.

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Amount of credit loss expense (reversal of expense) for financing receivable from change in methodology.

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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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The net gain (loss) resulting from sales and other disposals of other real estate owned, increases (decreases) in the valuation allowance for foreclosed real estate, and write-downs of other real estate owned after acquisition or physical possession.

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Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

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Amount before allowance and after 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.

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Amount, before valuation allowance, of financing receivable classified as held-for-sale.

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Amount of increase (decrease) of physical assets used in the normal conduct of business and not intended for resale, from reclassification, impairment, donation, or changes classified as other. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount of credit loss expense (reversal of expense) for financing receivable.

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Loans Held for Investment and Allowance for Credit Losses on Loans - Additional Information (Detail) - USD ($)		12 Months Ended
	Jan. 01, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment [Line Items]
Total loans		$ 6,169,442,000	$ 6,394,506,000
Paycheck protection program amortized processing fees recognized as interest income		36,400,000	15,500,000
Gains on sale of property held in other real estate owned		618,000,000	2,400,000	$ 1,400,000
Interest income that would have been recognized		2,200,000	2,800,000	1,700,000
Decrease in allowance for credit losses upon adoption of ASC 326	$ 3,200,000		3,195,000
Provision for credit losses on loans		(8,690,000)	62,648,000	$ 8,287,000
Interest income recognized on collateral-dependent loans		0	0
Commercial Real Estate
Financing Receivable Recorded Investment [Line Items]
Loans modification		53,900,000	81,700,000
U.S. Federal Agencies [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans guaranteed by government agencies		3,300,000
Previous Corporate Headquarters [Member] \| Other Real Estate Owned [Member]
Financing Receivable Recorded Investment [Line Items]
Transferred premises and equipment to other real estate		$ 2,400,000
BancFirst [Member]
Financing Receivable Recorded Investment [Line Items]
Loans held for sale			21,600,000
Amount transferred from loans held for investment (net of unearned interest) to loans held for sale			$ 21,600,000
Parent Company [Member]
Financing Receivable Recorded Investment [Line Items]
Percentage of loans secured by real estate		62.00%