Loans and Leases and the Allowance for Credit Losses - Loan and Leases Considered Nonaccrual and Interest Income Recognized on Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2023	Jan. 01, 2023	Mar. 31, 2022	Jan. 01, 2022
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	$ 882,869	$ 1,094,400	$ 882,869	$ 1,094,400
Amortized Cost without Allowance	1,552,712	1,538,605	1,552,712	1,538,605
Total	2,435,581	2,633,005	2,435,581	2,633,005
Amortized Cost					$ 2,556,799	$ 2,438,435	$ 2,134,231	$ 2,060,083
Interest Income Recognized	12,674	15,815	29,537	45,431
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	162,087	278,396	162,087	278,396
Amortized Cost without Allowance	253,935	164,100	253,935	164,100
Total	416,022	442,496	416,022	442,496
Amortized Cost					382,268	347,204	275,146	221,022
Interest Income Recognized	1,909	2,121	4,188	15,715
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	415,685	397,536	415,685	397,536
Amortized Cost without Allowance	967,505	1,079,122	967,505	1,079,122
Total	1,383,190	1,476,658	1,383,190	1,476,658
Amortized Cost					1,516,655	1,396,662	1,157,686	1,069,280
Interest Income Recognized	4,432	1,754	9,933	7,885
Residential Builder and Developer [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	1,193	518	1,193	518
Total	1,193	518	1,193	518
Amortized Cost					3,303	1,229	2,916	3,005
Interest Income Recognized	30	259	396	1,687
Other Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	44,489	36,345	44,489	36,345
Amortized Cost without Allowance	101,535	36,701	101,535	36,701
Total	146,024	73,046	146,024	73,046
Amortized Cost					143,015	124,937	50,855	111,405
Interest Income Recognized	63	2,750	1,725	3,376
Residential [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	91,371	175,019	91,371	175,019
Amortized Cost without Allowance	147,138	156,357	147,138	156,357
Total	238,509	331,376	238,509	331,376
Amortized Cost					253,646	272,090	341,671	355,858
Interest Income Recognized	4,391	6,797	8,767	13,338
Residential Limited Documentation [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	27,013	70,718	27,013	70,718
Amortized Cost without Allowance	39,601	41,890	39,601	41,890
Total	66,614	112,608	66,614	112,608
Amortized Cost					68,935	77,814	123,512	122,888
Interest Income Recognized	96	31	260	227
Home Equity Lines and Loans [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	48,513	30,328	48,513	30,328
Amortized Cost without Allowance	28,577	49,117	28,577	49,117
Total	77,090	79,445	77,090	79,445
Amortized Cost					80,766	84,788	71,489	70,488
Interest Income Recognized	1,458	1,813	3,679	2,622
Recreational Finance [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	23,005	26,530	23,005	26,530
Amortized Cost without Allowance	9,281	6,884	9,281	6,884
Total	32,286	33,414	32,286	33,414
Amortized Cost					34,186	44,630	31,546	27,811
Interest Income Recognized	180	161	351	322
Automobile [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	18,275	31,970	18,275	31,970
Amortized Cost without Allowance	3,516	4,296	3,516	4,296
Total	21,791	36,266	21,791	36,266
Amortized Cost					26,842	39,584	35,350	34,037
Interest Income Recognized	36	37	71	75
Other [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	51,238	47,040	51,238	47,040
Amortized Cost without Allowance	1,624	138	1,624	138
Total	52,862	47,178	52,862	47,178
Amortized Cost					$ 47,183	$ 49,497	$ 44,060	$ 44,289
Interest Income Recognized	$ 79	$ 92	$ 167	$ 184