LOANS HELD FOR INVESTMENT - Corporation's Aging of Loans Held for Investment Portfolio (Parenthetical) (Details) - USD ($)	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans with No ACL	$ 19,046,000	$ 16,391,000
Loans Past Due 90 days or more and Still Accruing	28,949,000	31,913,000
Nonaccrual	87,744,000	92,563,000
Loans held for investment	13,091,077,000	13,125,356,000
PCD Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans Past Due 90 days or more and Still Accruing	4,200,000	4,800,000
Florida region [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans with No ACL	0	0
Nonaccrual	11,800,000	11,300,000
Loans held for investment	2,545,362,000	2,498,164,000
30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	67,436,000	90,610,000
Residential Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,914,898,000	2,908,302,000
Residential Portfolio Segment [Member] \| Performing Financial Instruments [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,886,827,000	2,879,133,000
Residential Portfolio Segment [Member] \| Florida region [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	11,300,000	11,100,000
Loans held for investment	536,510,000	530,698,000
Residential Portfolio Segment [Member] \| Florida region [Member] \| Performing Financial Instruments [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	525,237,000	519,573,000
Residential Portfolio Segment [Member] \| Conventional Residential Mortgage Loans [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	5,529,000	6,069,000
Nonaccrual	28,071,000	29,169,000
Loans held for investment	2,826,559,000	2,819,582,000
Residential Portfolio Segment [Member] \| Conventional Residential Mortgage Loans [Member] \| Performing Financial Instruments [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,798,488,000	2,790,413,000
Residential Portfolio Segment [Member] \| Conventional Residential Mortgage Loans [Member] \| PCD Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans Past Due 90 days or more and Still Accruing	3,700,000	3,900,000
Residential Portfolio Segment [Member] \| Conventional Residential Mortgage Loans [Member] \| Florida region [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	535,178,000	529,613,000
Residential Portfolio Segment [Member] \| Conventional Residential Mortgage Loans [Member] \| Florida region [Member] \| Performing Financial Instruments [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	523,905,000	518,488,000
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] \| 30-59 Days Past Due [Member] \| Less Than Two Payments In Arrears [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	54,400,000	59,100,000
Residential Portfolio Segment [Member] \| FHA/VA Government-Guaranteed Loans [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans with No ACL	0	0
Loans Past Due 90 days or more and Still Accruing	15,532,000	15,776,000
Nonaccrual	0	0
Loans held for investment	88,339,000	88,720,000
Residential Portfolio Segment [Member] \| FHA/VA Government-Guaranteed Loans [Member] \| Performing Financial Instruments [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	88,339,000	88,720,000
Residential Portfolio Segment [Member] \| FHA/VA Government-Guaranteed Loans [Member] \| Florida region [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,332,000	1,085,000
Residential Portfolio Segment [Member] \| FHA/VA Government-Guaranteed Loans [Member] \| Florida region [Member] \| Performing Financial Instruments [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,332,000	1,085,000
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] \| 30-59 Days Past Due [Member] \| Less Than Two Payments In Arrears [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	7,400,000	8,700,000
Residential Portfolio Segment [Member] \| GNMA [Member] \| Repurchase Option Program [Member]
Financing Receivable, Past Due [Line Items]
Loans Past Due 90 days or more and Still Accruing	6,700,000	6,700,000
Residential Portfolio Segment [Member] \| Federal Housing Administration Loan [Member] \| Past Due, 15 Months Delinquent [Member]
Financing Receivable, Past Due [Line Items]
Loans Past Due 90 days or more and Still Accruing	3,900,000	4,100,000
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans with No ACL	956,000	956,000
Loans Past Due 90 days or more and Still Accruing	67,000	0
Nonaccrual	5,414,000	5,536,000
Loans held for investment	195,267,000	265,568,000
Commercial Portfolio Segment [Member] \| Construction Loans [Member] \| Florida region [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	2,290,000	1,928,000
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] \| Commercial and Industrial Sector [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans with No ACL	12,447,000	13,752,000
Loans Past Due 90 days or more and Still Accruing	1,248,000	2,730,000
Nonaccrual	27,100,000	28,042,000
Loans held for investment	3,694,843,000	3,688,358,000
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member] \| Florida region [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	500,000	200,000
Loans held for investment	1,200,142,000	1,169,356,000
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	636,000	1,514,000
Commercial Portfolio Segment [Member] \| Commercial Mortgage Loans [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual Loans with No ACL	4,558,000	952,000
Loans Past Due 90 days or more and Still Accruing	540,000	933,000
Nonaccrual	7,442,000	8,382,000
Loans held for investment	2,627,113,000	2,554,252,000
Commercial Portfolio Segment [Member] \| Commercial Mortgage Loans [Member] \| PCD Loans [Member]
Financing Receivable, Past Due [Line Items]
Loans Past Due 90 days or more and Still Accruing	500,000	900,000
Commercial Portfolio Segment [Member] \| Commercial Mortgage Loans [Member] \| Florida region [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	800,564,000	790,325,000
Commercial Portfolio Segment [Member] \| Commercial Mortgage Loans [Member] \| 30-59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	1,265,000	141,000
Commercial Portfolio Segment [Member] \| Commercial Mortgage Loans [Member] \| 30-59 Days Past Due [Member] \| Less Than Two Payments In Arrears [Member]
Financing Receivable, Past Due [Line Items]
Loans held for investment	$ 1,200,000	$ 800,000

Amortized cost excluding accrued interest, of financing receivable 90 days or more past due and still accruing. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-5

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (d)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (d)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 10: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-14

Reference 12: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 13: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 14: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (b)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 15: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 16: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-12

Reference 17: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 80
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-80

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration