Allowance for Credit Losses - Loan and Leases Considered Nonaccrual and Interest Income Recognized on Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2021	Jan. 01, 2020	Jan. 01, 2019
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	$ 789,228	$ 974,782	$ 399,274
Amortized Cost without Allowance	1,270,855	918,517	563,838
Total	2,060,083	1,893,299	963,112
Amortized Cost				$ 1,893,299	$ 1,134,333	$ 893,608
Interest Income Recognized	58,740	54,217	36,807
Commercial, Financial, Leasing, etc. [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	110,790	226,897	206,644
Amortized Cost without Allowance	110,232	79,930	139,913
Total	221,022	306,827	346,557
Amortized Cost				306,827	346,743	234,423
Interest Income Recognized	11,865	11,269	8,960
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	242,078	364,110	40,847
Amortized Cost without Allowance	827,202	411,784	117,627
Total	1,069,280	775,894	158,474
Amortized Cost				775,894	173,796	203,672
Interest Income Recognized	15,872	7,821	5,850
Residential Builder and Developer [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	613	1,094	604
Amortized Cost without Allowance	2,392		3,378
Total	3,005	1,094	3,982
Amortized Cost				1,094	4,708	4,798
Interest Income Recognized	973	1,694	357
Other Commercial Construction [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	30,229	20,992	12,425
Amortized Cost without Allowance	81,176	93,047	20,345
Total	111,405	114,039	32,770
Amortized Cost				114,039	35,881	22,205
Interest Income Recognized	596	8,457	634
Residential [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	198,560	159,006	59,982
Amortized Cost without Allowance	157,298	206,723	175,681
Total	355,858	365,729	235,663
Amortized Cost				365,729	322,504	233,352
Interest Income Recognized	23,772	18,069	12,630
Residential Limited Documentation [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	79,777	84,568	26,710
Amortized Cost without Allowance	43,111	62,602	56,717
Total	122,888	147,170	83,427
Amortized Cost				147,170	114,667	84,685
Interest Income Recognized	528	634	1,092
Home Equity Lines and Loans [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	32,269	61,031	24,812
Amortized Cost without Allowance	38,219	18,361	38,403
Total	70,488	79,392	63,215
Amortized Cost				79,392	65,039	71,292
Interest Income Recognized	3,780	4,092	5,987
Recreational Finance [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	21,476	19,434	9,054
Amortized Cost without Allowance	6,335	6,085	5,165
Total	27,811	25,519	14,219
Amortized Cost				25,519	14,308	11,199
Interest Income Recognized	637	626	575
Automobile [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	29,314	34,044	14,805
Amortized Cost without Allowance	4,723	5,360	6,488
Total	34,037	39,404	21,293
Amortized Cost				39,404	21,293	23,359
Interest Income Recognized	186	186	214
Other [Member]
Financing Receivable, Impaired [Line Items]
Amortized Cost with Allowance	44,122	3,606	3,391
Amortized Cost without Allowance	167	34,625	121
Total	44,289	38,231	3,512
Amortized Cost				$ 38,231	$ 35,394	$ 4,623
Interest Income Recognized	$ 531	$ 1,369	$ 508