LOANS HELD FOR INVESTMENT - Corporation's Aging of Loans Held for Investment Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Loans held for investment	$ 12,746,556	$ 12,185,483
Nonaccrual Loans with No ACL	11,972	6,953
Loans Past Due 90 days or more and Still Accruing	42,390	59,452
Financing Receivable, Nonaccrual	87,467	83,707
Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	12,463,724	11,891,511
30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	93,171	89,185
60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	59,804	61,628
Residential Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,828,431	2,821,726
Residential Portfolio Segment [Member] | Conventional Residential Mortgage Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,736,179	2,721,490
Nonaccrual Loans with No ACL	1,773	1,742
Loans Past Due 90 days or more and Still Accruing	7,404	11,029
Financing Receivable, Nonaccrual	31,949	32,239
Residential Portfolio Segment [Member] | Conventional Residential Mortgage Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,666,959	2,644,344
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	29,867	33,878
Residential Portfolio Segment [Member] | FHA/VA Government-Guaranteed Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	92,252	100,236
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	18,816	29,312
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	70,529	68,332
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	2,907	2,592
Commercial Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	228,396	214,777
Nonaccrual Loans with No ACL	968	972
Loans Past Due 90 days or more and Still Accruing	0	2,297
Financing Receivable, Nonaccrual	1,365	1,569
Commercial Portfolio Segment [Member] | Construction Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	227,031	210,911
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
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,565,984	2,317,083
Nonaccrual Loans with No ACL	6,732	2,536
Loans Past Due 90 days or more and Still Accruing	907	1,108
Financing Receivable, Nonaccrual	10,851	12,205
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,554,226	2,303,753
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	0	17
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	0	0
Commercial Portfolio Segment [Member] | Commercial and Industrial Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,366,038	3,174,232
Nonaccrual Loans with No ACL	1,189	1,687
Loans Past Due 90 days or more and Still Accruing	6,895	8,455
Financing Receivable, Nonaccrual	20,514	15,250
Commercial Portfolio Segment [Member] | Commercial and Industrial Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,336,465	3,148,254
Commercial Portfolio Segment [Member] | Commercial and Industrial Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,589	1,130
Commercial Portfolio Segment [Member] | Commercial and Industrial Loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	575	1,143
Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,757,707	3,657,665
Consumer Portfolio Segment [Member] | Auto loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,026,178	1,936,256
Nonaccrual Loans with No ACL	1,032	4
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	15,305	15,568
Consumer Portfolio Segment [Member] | Auto loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,935,995	1,846,652
Consumer Portfolio Segment [Member] | Auto loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	61,524	60,283
Consumer Portfolio Segment [Member] | Auto loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	13,354	13,753
Consumer Portfolio Segment [Member] | Finance Leases [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	899,446	856,815
Nonaccrual Loans with No ACL	275	12
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	3,812	3,287
Consumer Portfolio Segment [Member] | Finance Leases [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	875,663	837,881
Consumer Portfolio Segment [Member] | Finance Leases [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	15,879	13,786
Consumer Portfolio Segment [Member] | Finance Leases [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	4,092	1,861
Consumer Portfolio Segment [Member] | Personal Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	361,908	381,275
Nonaccrual Loans with No ACL	3	0
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	2,136	1,841
Consumer Portfolio Segment [Member] | Personal Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	349,588	370,746
Consumer Portfolio Segment [Member] | Personal Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	6,591	5,873
Consumer Portfolio Segment [Member] | Personal Loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,593	2,815
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	321,014	329,212
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	8,368	7,251
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	303,311	313,360
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	5,366	5,012
Consumer Portfolio Segment [Member] | Credit Card Receivables [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	3,969	3,589
Consumer Portfolio Segment [Member] | Other Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	149,161	154,107
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	0	0
Financing Receivable, Nonaccrual	1,535	1,748
Consumer Portfolio Segment [Member] | Other Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	143,957	147,278
Consumer Portfolio Segment [Member] | Other Loans [Member] | 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,222	3,084
Consumer Portfolio Segment [Member] | Other Loans [Member] | 60-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	$ 1,447	$ 1,997