Revenue Recognition - Summary of Disaggregation of Revenue According to Revenue Stream and Business Segment (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation Of Revenue [Line Items]
Revenue (Expense) out of Scope of ASC 606	$ 5,731	$ 1,043	$ 70,981	$ 31,481
Noninterest income	128,723	107,907	428,736	348,393
Trust and Securities Processing [Member]
Disaggregation Of Revenue [Line Items]
Noninterest income	59,586	56,914	178,000	165,611
Trading and Investment Banking [Member]
Disaggregation Of Revenue [Line Items]
Revenue (Expense) out of Scope of ASC 606	5,425	5,807	17,772	23,212
Noninterest income	5,387	5,936	17,950	23,962
Service Charges On Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue (Expense) out of Scope of ASC 606	33	88	153	236
Noninterest income	19,932	19,881	65,409	64,449
Insurance Fees and Commissions [Member]
Disaggregation Of Revenue [Line Items]
Noninterest income	375	285	879	950
Brokerage Fees [Member]
Disaggregation Of Revenue [Line Items]
Noninterest income	13,840	2,899	29,687	8,825
Bankcard Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue (Expense) out of Scope of ASC 606	(8,578)	(8,363)	(25,850)	(24,789)
Noninterest income	19,379	17,198	53,854	47,934
Investment Securities Gains (Losses), Net [Member]
Disaggregation Of Revenue [Line Items]
Revenue (Expense) out of Scope of ASC 606	(1,345)	(3,510)	58,853	3,609
Noninterest income	(1,345)	(3,510)	58,853	3,609
Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue (Expense) out of Scope of ASC 606	10,196	7,021	20,053	29,213
Noninterest income	11,569	8,304	24,104	33,053
Commercial Banking [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	25,281	23,719	73,157	67,772
Noninterest income	16,785	17,048	100,379	62,306
Commercial Banking [Member] \| Service Charges On Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	8,357	8,164	25,998	24,674
Commercial Banking [Member] \| Brokerage Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	66	16	174	90
Commercial Banking [Member] \| Bankcard Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	16,656	15,300	46,387	42,335
Commercial Banking [Member] \| Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	202	239	598	673
Institutional Banking [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	73,642	58,675	212,459	174,298
Noninterest income	89,386	65,568	243,740	202,769
Institutional Banking [Member] \| Trust and Securities Processing [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	46,385	42,697	137,225	120,300
Institutional Banking [Member] \| Trading and Investment Banking [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	(38)	129	178	750
Institutional Banking [Member] \| Service Charges On Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	9,564	9,867	33,704	34,876
Institutional Banking [Member] \| Brokerage Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	11,904	851	23,738	2,843
Institutional Banking [Member] \| Bankcard Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	5,350	4,727	16,234	14,310
Institutional Banking [Member] \| Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	477	404	1,380	1,219
Personal Banking [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	24,069	24,470	72,139	74,842
Noninterest income	22,552	25,291	84,617	83,318
Personal Banking [Member] \| Trust and Securities Processing [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	13,201	14,217	40,775	45,311
Personal Banking [Member] \| Service Charges On Deposit Accounts [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	1,978	1,762	5,554	4,663
Personal Banking [Member] \| Insurance Fees and Commissions [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	375	285	879	950
Personal Banking [Member] \| Brokerage Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	1,870	2,032	5,775	5,892
Personal Banking [Member] \| Bankcard Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	5,951	5,534	17,083	16,078
Personal Banking [Member] \| Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue Scope of ASC 606	$ 694	$ 640	$ 2,073	$ 1,948

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The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Amount of revenue that is not accounted for under Topic 606.

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