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		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2022	Apr. 01, 2022	Jan. 01, 2022	Jun. 30, 2021	Jan. 01, 2021
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	$ 1,005,944	$ 946,452	$ 1,005,944	$ 946,452
Amortized Cost without Allowance	1,423,382	1,295,811	1,423,382	1,295,811
Total	2,429,326	2,242,263	2,429,326	2,242,263		$ 3,410,506
Amortized Cost					$ 2,633,005	$ 99,000	$ 2,060,083	$ 2,242,057	$ 1,893,299
Interest Income Recognized	21,031	15,571	66,462	37,905
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	207,841	171,040	207,841	171,040
Amortized Cost without Allowance	160,325	109,149	160,325	109,149
Total	368,166	280,189	368,166	280,189
Amortized Cost					442,496		221,022	330,040	306,827
Interest Income Recognized	4,708	4,646	20,423	10,661
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	394,502	332,014	394,502	332,014
Amortized Cost without Allowance	1,011,698	820,856	1,011,698	820,856
Total	1,406,200	1,152,870	1,406,200	1,152,870
Amortized Cost					1,476,658		1,069,280	1,081,546	775,894
Interest Income Recognized	7,059	2,256	14,944	4,518
Residential Builder and Developer [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	1,930	594	1,930	594
Total	1,930	594	1,930	594
Amortized Cost					518		3,005	14,552	1,094
Interest Income Recognized		206	1,687	239
Other Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	25,235	36,750	25,235	36,750
Amortized Cost without Allowance	40,952	121,949	40,952	121,949
Total	66,187	158,699	66,187	158,699
Amortized Cost					73,046		111,405	133,758	114,039
Interest Income Recognized	22	255	3,398	570
Residential [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	160,704	196,918	160,704	196,918
Amortized Cost without Allowance	124,691	156,508	124,691	156,508
Total	285,395	353,426	285,395	353,426
Amortized Cost					331,376		355,858	372,144	365,729
Interest Income Recognized	8,059	6,809	21,397	17,603
Residential Limited Documentation [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	61,297	81,538	61,297	81,538
Amortized Cost without Allowance	34,085	44,991	34,085	44,991
Total	95,382	126,529	95,382	126,529
Amortized Cost					112,608		122,888	136,683	147,170
Interest Income Recognized	229	100	456	336
Home Equity Lines and Loans [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	38,324	38,582	38,324	38,582
Amortized Cost without Allowance	39,884	32,892	39,884	32,892
Total	78,208	71,474	78,208	71,474
Amortized Cost					79,445		70,488	76,711	79,392
Interest Income Recognized	669	979	3,291	2,924
Recreational Finance [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	31,295	18,428	31,295	18,428
Amortized Cost without Allowance	7,423	5,479	7,423	5,479
Total	38,718	23,907	38,718	23,907
Amortized Cost					33,414		27,811	23,276	25,519
Interest Income Recognized	166	164	488	478
Automobile [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	36,075	27,258	36,075	27,258
Amortized Cost without Allowance	4,243	3,744	4,243	3,744
Total	40,318	31,002	40,318	31,002
Amortized Cost					36,266		34,037	31,090	39,404
Interest Income Recognized	35	46	110	143
Other [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	48,741	43,330	48,741	43,330
Amortized Cost without Allowance	81	243	81	243
Total	48,822	43,573	48,822	43,573
Amortized Cost					$ 47,178		$ 44,289	$ 42,257	$ 38,231
Interest Income Recognized	$ 84	$ 110	$ 268	$ 433