Loans and Leases and the Allowance for Credit Losses - Loan Modification Activities that were Considered Troubled Debt Restructurings (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) Modification	Sep. 30, 2021 USD ($) Modification	Sep. 30, 2022 USD ($) Modification	Sep. 30, 2021 USD ($) Modification
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	839	395	2,691	1,742
Pre-modification Recorded Investment	$ 88,700	$ 125,101	$ 227,509	$ 511,038
Loans and leases, net of unearned discount	89,800	124,785	231,516	507,582
Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	48,275	56,116	160,742	196,378
Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	446		455
Other [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	351	40,504	3,206	71,296
Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	$ 40,728	$ 28,165	$ 67,113	$ 239,908
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	70	62	147	244
Pre-modification Recorded Investment	$ 32,451	$ 49,884	$ 79,437	$ 174,366
Loans and leases, net of unearned discount	33,431	49,772	81,371	173,377
Commercial, Financial, Leasing, etc. [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	11,237	6,051	49,671	42,143
Commercial, Financial, Leasing, etc. [Member] | Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	446		455
Commercial, Financial, Leasing, etc. [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	229	40,242	983	40,464
Commercial, Financial, Leasing, etc. [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	$ 21,519	$ 3,479	$ 30,262	$ 90,770
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	14	15	44	83
Pre-modification Recorded Investment	$ 22,951	$ 53,198	$ 33,349	$ 223,209
Loans and leases, net of unearned discount	22,887	53,172	33,003	221,129
Commercial Real Estate [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	7,222	30,311	13,052	48,841
Commercial Real Estate [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	122	262	2,223	30,832
Commercial Real Estate [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	$ 15,543	$ 22,599	$ 17,728	$ 141,456
Other Commercial Construction [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification				3
Pre-modification Recorded Investment				$ 542
Loans and leases, net of unearned discount				532
Other Commercial Construction [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount				$ 532
Residential [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	57	64	221	304
Pre-modification Recorded Investment	$ 14,380	$ 14,443	$ 56,912	$ 88,067
Loans and leases, net of unearned discount	14,564	14,265	59,290	87,802
Residential [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	11,094	12,281	40,821	80,411
Residential [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	$ 3,470	$ 1,984	$ 18,469	$ 7,391
Residential Limited Documentation [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	2	4	7	17
Pre-modification Recorded Investment	$ 155	$ 828	$ 1,231	$ 2,349
Loans and leases, net of unearned discount	155	828	1,242	2,292
Residential Limited Documentation [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	$ 155	$ 828	$ 1,049	$ 2,292
Home Equity Lines and Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	25	22	93	64
Pre-modification Recorded Investment	$ 1,700	$ 1,349	$ 6,483	$ 5,034
Loans and leases, net of unearned discount	1,700	1,349	6,550	4,979
Home Equity Lines and Loans [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	1,504	1,246	6,089	4,702
Home Equity Lines and Loans [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	$ 196	$ 103	$ 461	$ 277
Recreational Finance [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	167	67	514	173
Pre-modification Recorded Investment	$ 6,937	$ 2,565	$ 19,138	$ 5,896
Loans and leases, net of unearned discount	6,937	2,565	19,131	5,896
Recreational Finance [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	$ 6,937	$ 2,565	$ 19,131	$ 5,896
Automobile [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	474	146	1,537	516
Pre-modification Recorded Investment	$ 9,755	$ 2,711	$ 29,789	$ 9,182
Loans and leases, net of unearned discount	9,755	2,711	29,759	9,182
Automobile [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	$ 9,755	$ 2,711	$ 29,759	9,168
Automobile [Member] | Combination of Concession Types [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount				$ 14
Other [Member]
Financing Receivable, Modifications [Line Items]
Number of modifications | Modification	30	15	128	338
Pre-modification Recorded Investment	$ 371	$ 123	$ 1,170	$ 2,393
Loans and leases, net of unearned discount	371	123	1,170	2,393
Other [Member] | Principal Deferral [Member]
Financing Receivable, Modifications [Line Items]
Loans and leases, net of unearned discount	$ 371	$ 123	$ 1,170	$ 2,393