Loans and Leases and the Allowance for Credit Losses - Summary of loans in Accrual and Nonaccrual Status (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	$ 1,891,910	$ 1,779,054
Accruing Loans Past Due 90 Days or More	407,457	491,018
Nonaccrual	2,556,799	2,438,435
Loans and leases, net of unearned discount	132,937,692	131,564,163
Gross charge-offs	94,939
Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	26,700,228	26,197,545
Gross charge-offs	3,597
Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,651,876	1,664,096
Gross charge-offs	704
Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	496,225	595,897
Accruing Loans Past Due 90 Days or More	292,950	345,402
Nonaccrual	253,646	272,090
Loans and leases, net of unearned discount	22,769,784	22,704,895
Gross charge-offs	1,565
Residential [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	2,062	499
Nonaccrual	6,888	7,353
Loans and leases, net of unearned discount	33,201	38,292
Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	26,046	22,456
Nonaccrual	68,935	77,814
Loans and leases, net of unearned discount	1,020,161	1,051,052
Gross charge-offs	136
Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	26,679	30,787
Nonaccrual	80,766	84,788
Loans and leases, net of unearned discount	4,859,267	5,006,886
Gross charge-offs	2,033
Home Equity Lines and Loans [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual	1,880	2,799
Loans and leases, net of unearned discount	3,140,473	3,265,332
Gross charge-offs	1,298
Home Equity Lines and Loans [Member] | Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	25,025	28,460
Nonaccrual	70,696	74,646
Loans and leases, net of unearned discount	1,575,800	1,590,440
Gross charge-offs	704
Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	48,448	54,593
Nonaccrual	34,186	44,630
Loans and leases, net of unearned discount	9,149,221	9,073,394
Gross charge-offs	14,821
Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	35,270	44,486
Nonaccrual	26,842	39,584
Loans and leases, net of unearned discount	4,311,147	4,477,276
Gross charge-offs	6,711
Other [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	16,686	22,961
Accruing Loans Past Due 90 Days or More	4,977	4,869
Nonaccrual	47,183	49,497
Loans and leases, net of unearned discount	1,997,210	2,035,523
Gross charge-offs	20,286
Other [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	10,045	15,655
Accruing Loans Past Due 90 Days or More	4,779	4,643
Nonaccrual	43,631	44,449
Loans and leases, net of unearned discount	1,396,185	1,439,796
Gross charge-offs	20
Other [Member] | Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	544	651
Nonaccrual	116	185
Loans and leases, net of unearned discount	6,517	9,057
Current [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	128,081,526	126,855,656
Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	21,726,963	21,491,506
Current [Member] | Residential [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	24,251	30,440
Current [Member] | Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	925,180	950,782
Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,751,822	4,891,311
Current [Member] | Home Equity Lines and Loans [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,138,593	3,262,533
Current [Member] | Home Equity Lines and Loans [Member] | Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,480,079	1,487,334
Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,066,587	8,974,171
Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,249,035	4,393,206
Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,928,364	1,958,196
Current [Member] | Other [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,337,730	1,375,049
Current [Member] | Other [Member] | Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,857	8,221
Term Loans 2023 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	5,212,148
Gross charge-offs	1,019
Term Loans 2023 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	1,408
Loans and leases, net of unearned discount	498,546
Term Loans 2023 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	172
Term Loans 2023 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	280
Loans and leases, net of unearned discount	521,800
Term Loans 2023 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	397
Loans and leases, net of unearned discount	253,507
Term Loans 2023 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	2,119
Nonaccrual	1,711
Loans and leases, net of unearned discount	76,354
Gross charge-offs	912
Term Loans 2023 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	497,138
Term Loans 2023 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	172
Term Loans 2023 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	521,520
Term Loans 2023 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	253,110
Term Loans 2023 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	72,524
Term Loans 2022 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	24,189,798	24,853,925
Gross charge-offs	16,841
Term Loans 2022 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	55,995	59,477
Accruing Loans Past Due 90 Days or More	14,957	12,012
Nonaccrual	7,087	5,686
Loans and leases, net of unearned discount	5,134,638	5,148,554
Gross charge-offs	75
Term Loans 2022 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	33	930
Term Loans 2022 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	8,378	8,648
Nonaccrual	2,875	3,533
Loans and leases, net of unearned discount	2,722,698	2,854,272
Gross charge-offs	2,369
Term Loans 2022 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	6,688	6,926
Nonaccrual	2,669	2,493
Loans and leases, net of unearned discount	1,423,472	1,500,495
Gross charge-offs	1,636
Term Loans 2022 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	1,617	3,783
Nonaccrual	588	2,745
Loans and leases, net of unearned discount	248,635	281,058
Gross charge-offs	8,657
Term Loans 2022 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,056,599	5,071,379
Term Loans 2022 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	33	930
Term Loans 2022 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,711,445	2,842,091
Term Loans 2022 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,414,115	1,491,076
Term Loans 2022 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	246,430	274,530
Term Loans 2021 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	18,024,543	18,747,757
Gross charge-offs	11,336
Term Loans 2021 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	50,487	51,308
Accruing Loans Past Due 90 Days or More	28,430	39,934
Nonaccrual	12,270	10,865
Loans and leases, net of unearned discount	4,059,202	4,103,759
Gross charge-offs	115
Term Loans 2021 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	10
Nonaccrual	15	15
Loans and leases, net of unearned discount	2,032	2,124
Term Loans 2021 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	9,892	9,525
Nonaccrual	6,473	7,440
Loans and leases, net of unearned discount	2,187,565	2,297,592
Gross charge-offs	3,013
Term Loans 2021 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	10,828	13,324
Nonaccrual	8,430	10,698
Loans and leases, net of unearned discount	1,439,088	1,581,698
Gross charge-offs	2,068
Term Loans 2021 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	1,336	1,450
Nonaccrual	535	830
Loans and leases, net of unearned discount	158,530	174,518
Gross charge-offs	2,735
Term Loans 2021 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,968,015	4,001,652
Term Loans 2021 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,007	2,109
Term Loans 2021 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,171,200	2,280,627
Term Loans 2021 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,419,830	1,557,676
Term Loans 2021 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	156,659	172,238
Term Loans 2020 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	12,395,896	13,072,920
Gross charge-offs	8,323
Term Loans 2020 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	25,710	40,337
Accruing Loans Past Due 90 Days or More	17,231	20,067
Nonaccrual	2,528	2,583
Loans and leases, net of unearned discount	2,768,139	2,780,358
Gross charge-offs	21
Term Loans 2020 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	55
Loans and leases, net of unearned discount	2,320	2,441
Term Loans 2020 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	9,833	12,412
Nonaccrual	7,112	9,427
Loans and leases, net of unearned discount	1,528,415	1,609,468
Gross charge-offs	2,985
Term Loans 2020 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	5,844	7,284
Nonaccrual	4,674	7,372
Loans and leases, net of unearned discount	636,138	717,367
Gross charge-offs	1,169
Term Loans 2020 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	198	326
Nonaccrual	195	332
Loans and leases, net of unearned discount	51,433	58,997
Gross charge-offs	1,395
Term Loans 2020 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,722,670	2,717,371
Term Loans 2020 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,265	2,441
Term Loans 2020 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,511,470	1,587,629
Term Loans 2020 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	625,620	702,711
Term Loans 2020 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	51,040	58,339
Term Loans 2019 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	12,015,988	12,737,602
Gross charge-offs	33,711
Term Loans 2019 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	19,711	21,849
Accruing Loans Past Due 90 Days or More	11,726	14,050
Nonaccrual	8,859	9,860
Loans and leases, net of unearned discount	1,400,328	1,438,625
Gross charge-offs	68
Term Loans 2019 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	26	171
Nonaccrual	65	536
Loans and leases, net of unearned discount	15,159	16,068
Term Loans 2019 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	7,475	8,387
Nonaccrual	5,256	7,625
Loans and leases, net of unearned discount	931,315	979,919
Gross charge-offs	2,412
Term Loans 2019 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	5,330	7,239
Nonaccrual	4,445	7,520
Loans and leases, net of unearned discount	338,281	393,721
Gross charge-offs	957
Term Loans 2019 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	272	386
Nonaccrual	149	371
Loans and leases, net of unearned discount	31,978	39,196
Gross charge-offs	1,581
Term Loans 2019 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,360,032	1,392,866
Term Loans 2019 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	15,068	15,361
Term Loans 2019 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	918,584	963,907
Term Loans 2019 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	328,506	378,962
Term Loans 2019 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	31,557	38,439
Term Loans 2018 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount		7,534,367
Term Loans 2018 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due		23,126
Accruing Loans Past Due 90 Days or More		14,007
Nonaccrual		4,650
Loans and leases, net of unearned discount		795,691
Term Loans 2018 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due		126
Nonaccrual		334
Loans and leases, net of unearned discount		23,781
Term Loans 2018 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due		5,202
Nonaccrual		5,344
Loans and leases, net of unearned discount		497,510
Term Loans 2018 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due		5,464
Nonaccrual		5,620
Loans and leases, net of unearned discount		178,522
Term Loans 2018 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due		141
Nonaccrual		120
Loans and leases, net of unearned discount		8,478
Term Loans 2018 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans		753,908
Term Loans 2018 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans		23,321
Term Loans 2018 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans		486,964
Term Loans 2018 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans		167,438
Term Loans 2018 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans		8,217
Term Loans Prior Period [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	32,747,215	26,755,951
Gross charge-offs	19,408
Term Loans Prior Period [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	340,852	399,301
Accruing Loans Past Due 90 Days or More	220,606	245,332
Nonaccrual	216,014	231,093
Loans and leases, net of unearned discount	8,875,730	8,399,616
Gross charge-offs	1,286
Term Loans Prior Period [Member] | Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	26,046	22,456
Nonaccrual	68,935	77,814
Loans and leases, net of unearned discount	1,020,161	1,051,052
Gross charge-offs	136
Term Loans Prior Period [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	1,563	2,030
Nonaccrual	8,110	6,458
Loans and leases, net of unearned discount	123,278	105,770
Gross charge-offs	31
Term Loans Prior Period [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	12,590	10,419
Nonaccrual	12,470	11,261
Loans and leases, net of unearned discount	1,257,428	834,633
Gross charge-offs	4,042
Term Loans Prior Period [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	6,183	4,249
Nonaccrual	6,624	5,881
Loans and leases, net of unearned discount	220,661	105,473
Gross charge-offs	881
Term Loans Prior Period [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	555	569
Accruing Loans Past Due 90 Days or More	198	226
Nonaccrual	258	465
Loans and leases, net of unearned discount	27,578	24,423
Gross charge-offs	4,986
Term Loans Prior Period [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	8,098,258	7,523,890
Term Loans Prior Period [Member] | Current [Member] | Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	925,180	950,782
Term Loans Prior Period [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	113,605	97,282
Term Loans Prior Period [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,232,368	812,953
Term Loans Prior Period [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	207,854	95,343
Term Loans Prior Period [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 26,567	$ 23,163