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, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Apr. 01, 2022	Mar. 31, 2022	Jan. 01, 2022	Mar. 31, 2021	Jan. 01, 2021
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	$ 1,094,400	$ 1,001,103	$ 1,094,400	$ 1,001,103
Amortized Cost without Allowance	1,538,605	1,240,954	1,538,605	1,240,954
Total	2,633,005	2,242,057	2,633,005	2,242,057	$ 3,410,506
Amortized Cost					$ 99,000	$ 2,134,231	$ 2,060,083	$ 1,957,106	$ 1,893,299
Interest Income Recognized	15,815	11,604	45,431	22,334
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	278,396	210,294	278,396	210,294
Amortized Cost without Allowance	164,100	119,746	164,100	119,746
Total	442,496	330,040	442,496	330,040
Amortized Cost						275,146	221,022	295,069	306,827
Interest Income Recognized	2,121	2,930	15,715	6,015
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	397,536	366,166	397,536	366,166
Amortized Cost without Allowance	1,079,122	715,380	1,079,122	715,380
Total	1,476,658	1,081,546	1,476,658	1,081,546
Amortized Cost						1,157,686	1,069,280	824,079	775,894
Interest Income Recognized	1,754	604	7,885	2,262
Residential Builder and Developer [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	518	1,093	518	1,093
Amortized Cost without Allowance		13,459		13,459
Total	518	14,552	518	14,552
Amortized Cost						2,916	3,005	1,224	1,094
Interest Income Recognized	259		1,687	33
Other Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	36,345	20,717	36,345	20,717
Amortized Cost without Allowance	36,701	113,041	36,701	113,041
Total	73,046	133,758	73,046	133,758
Amortized Cost						50,855	111,405	126,225	114,039
Interest Income Recognized	2,750	274	3,376	315
Residential [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	175,019	191,965	175,019	191,965
Amortized Cost without Allowance	156,357	180,179	156,357	180,179
Total	331,376	372,144	331,376	372,144
Amortized Cost						341,671	355,858	385,508	365,729
Interest Income Recognized	6,797	6,296	13,338	10,794
Residential Limited Documentation [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	70,718	85,683	70,718	85,683
Amortized Cost without Allowance	41,890	51,000	41,890	51,000
Total	112,608	136,683	112,608	136,683
Amortized Cost						123,512	122,888	143,069	147,170
Interest Income Recognized	31	157	227	236
Home Equity Lines and Loans [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	30,328	38,860	30,328	38,860
Amortized Cost without Allowance	49,117	37,851	49,117	37,851
Total	79,445	76,711	79,445	76,711
Amortized Cost						71,489	70,488	79,188	79,392
Interest Income Recognized	1,813	993	2,622	1,945
Recreational Finance [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	26,530	16,620	26,530	16,620
Amortized Cost without Allowance	6,884	6,656	6,884	6,656
Total	33,414	23,276	33,414	23,276
Amortized Cost						31,546	27,811	27,218	25,519
Interest Income Recognized	161	159	322	314
Automobile [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	31,970	27,609	31,970	27,609
Amortized Cost without Allowance	4,296	3,481	4,296	3,481
Total	36,266	31,090	36,266	31,090
Amortized Cost						35,350	34,037	38,219	39,404
Interest Income Recognized	37	48	75	97
Other [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	47,040	42,096	47,040	42,096
Amortized Cost without Allowance	138	161	138	161
Total	47,178	42,257	47,178	42,257
Amortized Cost						$ 44,060	$ 44,289	$ 37,307	$ 38,231
Interest Income Recognized	$ 92	$ 143	$ 184	$ 323