LOANS HELD FOR INVESTMENT - Loan Restructuring and Effect on Allowance for Loan and Lease Losses (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Loans and Leases Receivable Disclosure [Abstract]
Impact of adopting ASC 326	$ (23,600)
Provision for credit losses - (benefit) expense	(16,989)	$ (14,443)
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Abstract]
Impact of adopting ASC 326	(22,300)
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Loans and Leases Receivable Disclosure [Abstract]
Provision for credit losses - (benefit) expense	(2,214)	(456)
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member]
Loans and Leases Receivable Disclosure [Abstract]
Provision for credit losses - (benefit) expense	(22,640)	(8,820)
Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member]
Loans and Leases Receivable Disclosure [Abstract]
Provision for credit losses - (benefit) expense	1,755	(5,312)
Entity Loan Modification Program [Member]
Financing Receivable, Troubled Debt Restructuring [Abstract]
Beginning Balance of TDRs	414,738	479,196
New TDRs loan splits	4,670	3,019
Increases to existing TDRs	45	34
Charge-offs post modification	(881)	(2,909)
Paid-off, partial payments and other	(13,134)	(12,247)
Ending balance of TDRs	404,749	$ 460,204
Entity Loan Modification Program [Member] \| Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Abstract]
Beginning Balance of TDRs	2,303
Ending balance of TDRs	1,986
Entity Loan Modification Program [Member] \| Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member]
Financing Receivable, Troubled Debt Restructuring [Abstract]
Beginning Balance of TDRs	68,833
Ending balance of TDRs	67,688
Entity Loan Modification Program [Member] \| Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member]
Financing Receivable, Troubled Debt Restructuring [Abstract]
Beginning Balance of TDRs	70,420
Ending balance of TDRs	$ 68,545

Disbursements during the period on existing commitments of TDRs loans.

No definition available.

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- Definition

Recorded investment in loans that were modified under troubled debt restructurings during the period.

+ References

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- Definition

Repayments related to Trouble Debt Restructuring Loans.

+ References

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Amount of increase (decrease) in allowance for credit loss on financing receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447

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- Definition

Amount of financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

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Reflects the amount of the write-down related to a troubled debt restructuring.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
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-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

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Amount of expense related to estimated loss from loan and lease transactions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

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