LOANS HELD FOR INVESTMENT - Corporation's Aging of Loans Held for Investment Portfolio (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Loans held for investment	$ 12,185,483	$ 11,552,825
Nonaccrual Loans with No ACL	6,953	25,026
Loans Past Due 90 days or more and Still Accruing	59,452	80,283
Financing Receivable, Nonaccrual	83,707	89,935
Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	11,891,511	11,277,708
30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	89,185	58,718
60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	61,628	46,181
Residential Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,821,726	2,847,290
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,721,490	2,729,132
Nonaccrual Loans with No ACL	1,742	2,292
Loans Past Due 90 days or more and Still Accruing	11,029	16,821
Financing Receivable, Nonaccrual	32,239	42,772
Residential Portfolio Segment [Member] | Conventional residential mortgage loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,644,344	2,643,909
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	33,878	25,630
Residential Portfolio Segment [Member] | FHA/VA government-guaranteed loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	100,236	118,158
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	29,312	48,456
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	68,332	67,116
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	2,592	2,586
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,174,232	2,886,263
Nonaccrual Loans with No ACL	1,687	3,300
Loans Past Due 90 days or more and Still Accruing	8,455	6,332
Financing Receivable, Nonaccrual	15,250	7,830
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,148,254	2,868,989
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	1,130	1,984
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	1,143	1,128
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,317,083	2,358,851
Nonaccrual Loans with No ACL	2,536	15,991
Loans Past Due 90 days or more and Still Accruing	1,108	3,771
Financing Receivable, Nonaccrual	12,205	22,319
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,303,753	2,330,094
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	17	300
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	0	2,367
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	214,777	132,953
Nonaccrual Loans with No ACL	972	977
Loans Past Due 90 days or more and Still Accruing	2,297	128
Financing Receivable, Nonaccrual	1,569	2,208
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	210,911	130,617
Commercial Portfolio Segment [Member] | Construction Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	0	0
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	3,657,665	3,327,468
Consumer Portfolio Segment [Member] | Auto loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,936,256	1,798,071
Nonaccrual Loans with No ACL	4	2,136
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	15,568	10,672
Consumer Portfolio Segment [Member] | Auto loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,846,652	1,740,271
Consumer Portfolio Segment [Member] | Auto loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	60,283	40,039
Consumer Portfolio Segment [Member] | Auto loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	13,753	7,089
Consumer Portfolio Segment [Member] | Finance Leases [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	856,815	718,230
Nonaccrual Loans with No ACL	12	330
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	3,287	1,645
Consumer Portfolio Segment [Member] | Finance Leases [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	837,881	707,646
Consumer Portfolio Segment [Member] | Finance Leases [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	13,786	7,148
Consumer Portfolio Segment [Member] | Finance Leases [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,861	1,791
Consumer Portfolio Segment [Member] | Personal Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	381,275	353,246
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	1,841	1,248
Consumer Portfolio Segment [Member] | Personal Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	370,746	346,366
Consumer Portfolio Segment [Member] | Personal Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	5,873	3,738
Consumer Portfolio Segment [Member] | Personal Loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,815	1,894
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	329,212	311,731
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	7,251	4,775
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	313,360	301,013
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	5,012	3,705
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,589	2,238
Consumer Portfolio Segment [Member] | Other Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	154,107	146,190
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	1,748	1,241
Consumer Portfolio Segment [Member] | Other Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	147,278	141,687
Consumer Portfolio Segment [Member] | Other Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,084	1,804
Consumer Portfolio Segment [Member] | Other Loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	$ 1,997	$ 1,458