LOANS HELD FOR INVESTMENT - Corporation's Aging of Loans Held for Investment Portfolio (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Loans held for investment	$ 11,552,825	$ 11,060,658
Nonaccrual Loans with No ACL	25,026	27,733
Loans Past Due 90 days or more and Still Accruing	80,283	114,679
Financing Receivable, Nonaccrual	89,935	110,717
Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	11,277,708	10,744,930
30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	58,718	44,202
60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	46,181	46,130
Residential Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,847,290	2,978,895
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,729,132	2,853,503
Nonaccrual Loans with No ACL	2,292	3,689
Loans Past Due 90 days or more and Still Accruing	16,821	28,433
Financing Receivable, Nonaccrual	42,772	55,127
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,643,909	2,738,111
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	0	0
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	25,630	31,832
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	118,158	125,392
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	48,456	65,515
Financing Receivable, Nonaccrual	0	0
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	67,116	57,522
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	0	0
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,586	2,355
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,886,263	2,887,251
Nonaccrual Loans with No ACL	3,300	11,393
Loans Past Due 90 days or more and Still Accruing	6,332	7,827
Financing Receivable, Nonaccrual	7,830	17,135
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,868,989	2,858,397
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,984	2,047
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,128	1,845
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,358,851	2,167,469
Nonaccrual Loans with No ACL	15,991	8,289
Loans Past Due 90 days or more and Still Accruing	3,771	9,919
Financing Receivable, Nonaccrual	22,319	25,337
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,330,094	2,129,375
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	300	2,402
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,367	436
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	132,953	138,999
Nonaccrual Loans with No ACL	977	1,000
Loans Past Due 90 days or more and Still Accruing	128	0
Financing Receivable, Nonaccrual	2,208	2,664
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	130,617	136,317
Commercial Portfolio Segment [Member] | Construction Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	0	18
Commercial Portfolio Segment [Member] | Construction Loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	0	0
Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,327,468	2,888,044
Consumer Portfolio Segment [Member] | Auto loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,798,071	1,571,540
Nonaccrual Loans with No ACL	2,136	3,146
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	10,672	6,684
Consumer Portfolio Segment [Member] | Auto loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,740,271	1,533,445
Consumer Portfolio Segment [Member] | Auto loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	40,039	26,462
Consumer Portfolio Segment [Member] | Auto loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	7,089	4,949
Consumer Portfolio Segment [Member] | Finance Leases [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	718,230	575,005
Nonaccrual Loans with No ACL	330	196
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	1,645	866
Consumer Portfolio Segment [Member] | Finance Leases [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	707,646	568,606
Consumer Portfolio Segment [Member] | Finance Leases [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	7,148	4,820
Consumer Portfolio Segment [Member] | Finance Leases [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,791	713
Consumer Portfolio Segment [Member] | Personal Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	353,246	316,182
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	1,248	1,208
Consumer Portfolio Segment [Member] | Personal Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	346,366	310,390
Consumer Portfolio Segment [Member] | Personal Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,738	3,299
Consumer Portfolio Segment [Member] | Personal Loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,894	1,285
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	311,731	290,226
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	4,775	2,985
Financing Receivable, Nonaccrual	0	0
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	301,013	282,179
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,705	3,158
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,238	1,904
Consumer Portfolio Segment [Member] | Other Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	146,190	135,091
Nonaccrual Loans with No ACL	0	20
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	1,241	1,696
Consumer Portfolio Segment [Member] | Other Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	141,687	130,588
Consumer Portfolio Segment [Member] | Other Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,804	1,996
Consumer Portfolio Segment [Member] | Other Loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	$ 1,458	$ 811