LOANS HELD FOR INVESTMENT - Corporation's TDR Activity (Parenthetical) (Detail) - TDR - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Financing Receivable Modifications [Line Items]
Financing Receivable Modifications Troubled Debt Restructurings Paid Or Partial Paid	$ 13,134	$ 12,247
Charge-offs post modification	$ (881)	$ (2,909)

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

Name:	us-gaap_FinancingReceivablesImpairedTroubledDebtRestructuringWriteDown
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration