Loans and Leases and the Allowance for Credit Losses - Summary of loans in Accrual and Nonaccrual Status (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	$ 1,656,111	$ 1,656,111	$ 1,779,054
Accruing Loans Past Due 90 Days or More	380,079	380,079	491,018
Nonaccrual	2,435,581	2,435,581	2,438,435
Loans and leases, net of unearned discount	133,343,729	133,343,729	131,564,163
Gross charge-offs	162,224	257,163
Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	27,577,066	27,577,066	26,197,545
Gross charge-offs	344	3,941
Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	1,638,001	1,638,001	1,664,096
Gross charge-offs	1,113	1,817
Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	581,806	581,806	595,897
Accruing Loans Past Due 90 Days or More	284,410	284,410	345,402
Nonaccrual	238,509	238,509	272,090
Loans and leases, net of unearned discount	22,771,049	22,771,049	22,704,895
Gross charge-offs	845	2,410
Residential [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	87	87	499
Nonaccrual	6,679	6,679	7,353
Loans and leases, net of unearned discount	87,069	87,069	38,292
Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	23,945	23,945	22,456
Nonaccrual	66,614	66,614	77,814
Loans and leases, net of unearned discount	991,168	991,168	1,051,052
Gross charge-offs	227	363
Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,669,522	4,669,522
30-89 Days Past Due	26,478	26,478	30,787
Nonaccrual	77,090	77,090	84,788
Loans and leases, net of unearned discount	4,773,090	4,773,090	5,006,886
Gross charge-offs	1,166	3,199
Home Equity Lines and Loans [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,082,721	3,082,721
Nonaccrual	1,140	1,140	2,799
Loans and leases, net of unearned discount	3,083,861	3,083,861	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]
Total loans	1,459,491	1,459,491
30-89 Days Past Due	24,444	24,444	28,460
Nonaccrual	69,555	69,555	74,646
Loans and leases, net of unearned discount	1,553,490	1,553,490	1,590,440
Gross charge-offs	1,113	1,817
Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,171,034	9,171,034
30-89 Days Past Due	53,483	53,483	54,593
Nonaccrual	32,286	32,286	44,630
Loans and leases, net of unearned discount	9,256,803	9,256,803	9,073,394
Gross charge-offs	14,480	29,301
Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,020,722	4,020,722
30-89 Days Past Due	40,974	40,974	44,486
Nonaccrual	21,791	21,791	39,584
Loans and leases, net of unearned discount	4,083,487	4,083,487	4,477,276
Gross charge-offs	4,931	11,642
Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,062,277	2,062,277
30-89 Days Past Due	15,769	15,769	22,961
Accruing Loans Past Due 90 Days or More	4,964	4,964	4,869
Nonaccrual	52,862	52,862	49,497
Loans and leases, net of unearned discount	2,135,872	2,135,872	2,035,523
Gross charge-offs	17,728	38,014
Other [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,444,863	1,444,863
30-89 Days Past Due	8,979	8,979	15,655
Accruing Loans Past Due 90 Days or More	4,783	4,783	4,643
Nonaccrual	49,565	49,565	44,449
Loans and leases, net of unearned discount	1,508,190	1,508,190	1,439,796
Gross charge-offs	172	192
Other [Member] | Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,448	5,448
30-89 Days Past Due	530	530	651
Nonaccrual	156	156	185
Loans and leases, net of unearned discount	6,134	6,134	9,057
Current [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	128,871,958	128,871,958	126,855,656
Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	21,666,324	21,666,324	21,491,506
Current [Member] | Residential [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	80,303	80,303	30,440
Current [Member] | Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	900,609	900,609	950,782
Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,669,522	4,669,522	4,891,311
Current [Member] | Home Equity Lines and Loans [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			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			1,487,334
Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,171,034	9,171,034	8,974,171
Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,020,722	4,020,722	4,393,206
Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,062,277	2,062,277	1,958,196
Current [Member] | Other [Member] | Revolving Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			1,375,049
Current [Member] | Other [Member] | Revolving Loans Converted to Term Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			8,221
Term Loans 2023 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	9,682,358	9,682,358
Gross charge-offs	6,883	7,902
Term Loans 2023 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	4,818	4,818
Accruing Loans Past Due 90 Days or More	170	170
Nonaccrual	140	140
Loans and leases, net of unearned discount	1,083,740	1,083,740
Term Loans 2023 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	32	32
Loans and leases, net of unearned discount	32	32
Term Loans 2023 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,111,625	1,111,625
30-89 Days Past Due	1,345	1,345
Nonaccrual	554	554
Loans and leases, net of unearned discount	1,113,524	1,113,524
Gross charge-offs	873	873
Term Loans 2023 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	442,880	442,880
30-89 Days Past Due	1,731	1,731
Nonaccrual	648	648
Loans and leases, net of unearned discount	445,259	445,259
Gross charge-offs	81	81
Term Loans 2023 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	154,995	154,995
30-89 Days Past Due	2,113	2,113
Nonaccrual	1,434	1,434
Loans and leases, net of unearned discount	158,542	158,542
Gross charge-offs	5,201	6,113
Term Loans 2023 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,078,612	1,078,612
Term Loans 2022 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	23,151,528	23,151,528	24,853,925
Gross charge-offs	14,079	30,920
Term Loans 2022 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	77,407	77,407	59,477
Accruing Loans Past Due 90 Days or More	24,637	24,637	12,012
Nonaccrual	12,497	12,497	5,686
Loans and leases, net of unearned discount	5,031,169	5,031,169	5,148,554
Gross charge-offs	58	133
Term Loans 2022 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	31	31
Loans and leases, net of unearned discount	31	31	930
Term Loans 2022 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,572,098	2,572,098
30-89 Days Past Due	9,290	9,290	8,648
Nonaccrual	2,977	2,977	3,533
Loans and leases, net of unearned discount	2,584,365	2,584,365	2,854,272
Gross charge-offs	2,781	5,150
Term Loans 2022 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,298,446	1,298,446
30-89 Days Past Due	9,576	9,576	6,926
Nonaccrual	2,521	2,521	2,493
Loans and leases, net of unearned discount	1,310,543	1,310,543	1,500,495
Gross charge-offs	1,183	2,819
Term Loans 2022 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	222,468	222,468
30-89 Days Past Due	1,885	1,885	3,783
Nonaccrual	665	665	2,745
Loans and leases, net of unearned discount	225,018	225,018	281,058
Gross charge-offs	3,203	11,860
Term Loans 2022 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	4,916,628	4,916,628	5,071,379
Term Loans 2022 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			930
Term Loans 2022 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			2,842,091
Term Loans 2022 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			1,491,076
Term Loans 2022 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			274,530
Term Loans 2021 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	17,136,736	17,136,736	18,747,757
Gross charge-offs	11,973	23,309
Term Loans 2021 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	49,908	49,908	51,308
Accruing Loans Past Due 90 Days or More	26,574	26,574	39,934
Nonaccrual	14,259	14,259	10,865
Loans and leases, net of unearned discount	3,995,065	3,995,065	4,103,759
Gross charge-offs	77	192
Term Loans 2021 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,962	1,962
Nonaccrual	32	32	15
Loans and leases, net of unearned discount	1,994	1,994	2,124
Term Loans 2021 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,047,511	2,047,511
30-89 Days Past Due	12,008	12,008	9,525
Nonaccrual	6,984	6,984	7,440
Loans and leases, net of unearned discount	2,066,503	2,066,503	2,297,592
Gross charge-offs	3,014	6,027
Term Loans 2021 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,285,910	1,285,910
30-89 Days Past Due	12,148	12,148	13,324
Nonaccrual	7,163	7,163	10,698
Loans and leases, net of unearned discount	1,305,221	1,305,221	1,581,698
Gross charge-offs	1,916	3,984
Term Loans 2021 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	142,584	142,584
30-89 Days Past Due	1,304	1,304	1,450
Nonaccrual	445	445	830
Loans and leases, net of unearned discount	144,333	144,333	174,518
Gross charge-offs	2,261	4,996
Term Loans 2021 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,904,324	3,904,324	4,001,652
Term Loans 2021 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			2,109
Term Loans 2021 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			2,280,627
Term Loans 2021 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			1,557,676
Term Loans 2021 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			172,238
Term Loans 2020 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	11,904,481	11,904,481	13,072,920
Gross charge-offs	9,086	17,409
Term Loans 2020 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	33,051	33,051	40,337
Accruing Loans Past Due 90 Days or More	16,174	16,174	20,067
Nonaccrual	2,286	2,286	2,583
Loans and leases, net of unearned discount	2,715,220	2,715,220	2,780,358
Gross charge-offs		21
Term Loans 2020 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,164	2,164
30-89 Days Past Due	55	55
Loans and leases, net of unearned discount	2,219	2,219	2,441
Term Loans 2020 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,420,955	1,420,955
30-89 Days Past Due	10,542	10,542	12,412
Nonaccrual	5,775	5,775	9,427
Loans and leases, net of unearned discount	1,437,272	1,437,272	1,609,468
Gross charge-offs	2,746	5,731
Term Loans 2020 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	553,840	553,840
30-89 Days Past Due	6,187	6,187	7,284
Nonaccrual	3,988	3,988	7,372
Loans and leases, net of unearned discount	564,015	564,015	717,367
Gross charge-offs	708	1,877
Term Loans 2020 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	44,462	44,462
30-89 Days Past Due	235	235	326
Nonaccrual	135	135	332
Loans and leases, net of unearned discount	44,832	44,832	58,997
Gross charge-offs	1,209	2,604
Term Loans 2020 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,663,709	2,663,709	2,717,371
Term Loans 2020 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			2,441
Term Loans 2020 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			1,587,629
Term Loans 2020 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			702,711
Term Loans 2020 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			58,339
Term Loans 2019 [Member]
Financing Receivable Recorded Investment [Line Items]
Loans and leases, net of unearned discount	11,361,552	11,361,552	12,737,602
Gross charge-offs	57,412	91,123
Term Loans 2019 [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	23,741	23,741	21,849
Accruing Loans Past Due 90 Days or More	13,590	13,590	14,050
Nonaccrual	8,254	8,254	9,860
Loans and leases, net of unearned discount	1,312,134	1,312,134	1,438,625
Gross charge-offs	71	139
Term Loans 2019 [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	14,100	14,100
30-89 Days Past Due	309	309	171
Nonaccrual	65	65	536
Loans and leases, net of unearned discount	14,474	14,474	16,068
Term Loans 2019 [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	866,786	866,786
30-89 Days Past Due	7,690	7,690	8,387
Nonaccrual	4,706	4,706	7,625
Loans and leases, net of unearned discount	879,182	879,182	979,919
Gross charge-offs	1,751	4,163
Term Loans 2019 [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	280,257	280,257
30-89 Days Past Due	5,479	5,479	7,239
Nonaccrual	3,299	3,299	7,520
Loans and leases, net of unearned discount	289,035	289,035	393,721
Gross charge-offs	526	1,483
Term Loans 2019 [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	25,013	25,013
30-89 Days Past Due	221	221	386
Nonaccrual	127	127	371
Loans and leases, net of unearned discount	25,361	25,361	39,196
Gross charge-offs	1,334	2,915
Term Loans 2019 [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,266,549	1,266,549	1,392,866
Term Loans 2019 [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			15,361
Term Loans 2019 [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			963,907
Term Loans 2019 [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			378,962
Term Loans 2019 [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			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	30,892,007	30,892,007	26,755,951
Gross charge-offs	61,334	80,742
Term Loans Prior Period [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	392,794	392,794	399,301
Accruing Loans Past Due 90 Days or More	203,265	203,265	245,332
Nonaccrual	194,394	194,394	231,093
Loans and leases, net of unearned discount	8,546,652	8,546,652	8,399,616
Gross charge-offs	639	1,925
Term Loans Prior Period [Member] | Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
30-89 Days Past Due	23,945	23,945	22,456
Nonaccrual	66,614	66,614	77,814
Loans and leases, net of unearned discount	991,168	991,168	1,051,052
Gross charge-offs	227	363
Term Loans Prior Period [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	109,021	109,021
30-89 Days Past Due	1,670	1,670	2,030
Nonaccrual	6,298	6,298	6,458
Loans and leases, net of unearned discount	116,989	116,989	105,770
Gross charge-offs	53	84
Term Loans Prior Period [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,152,059	1,152,059
30-89 Days Past Due	12,608	12,608	10,419
Nonaccrual	11,290	11,290	11,261
Loans and leases, net of unearned discount	1,175,957	1,175,957	834,633
Gross charge-offs	3,315	7,357
Term Loans Prior Period [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	159,389	159,389
30-89 Days Past Due	5,853	5,853	4,249
Nonaccrual	4,172	4,172	5,881
Loans and leases, net of unearned discount	169,414	169,414	105,473
Gross charge-offs	517	1,398
Term Loans Prior Period [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	22,444	22,444
30-89 Days Past Due	502	502	569
Accruing Loans Past Due 90 Days or More	181	181	226
Nonaccrual	335	335	465
Loans and leases, net of unearned discount	23,462	23,462	24,423
Gross charge-offs	4,348	9,334
Term Loans Prior Period [Member] | Current [Member] | Residential [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	7,756,199	7,756,199	7,523,890
Term Loans Prior Period [Member] | Current [Member] | Residential Limited Documentation [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 900,609	$ 900,609	950,782
Term Loans Prior Period [Member] | Current [Member] | Home Equity Lines and Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			97,282
Term Loans Prior Period [Member] | Current [Member] | Recreational Finance [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			812,953
Term Loans Prior Period [Member] | Current [Member] | Automobile [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			95,343
Term Loans Prior Period [Member] | Current [Member] | Other [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans			$ 23,163