LOANS HELD FOR INVESTMENT, NET - Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment		$ 17,069
Individually evaluated for impairment		6,474
Commercial and industrial ("C&I")
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment		12,502
Individually evaluated for impairment		$ 6,474
Collateral Dependent Loans \| Commercial and industrial ("C&I")
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment	$ 8,000
Individually evaluated for impairment	4,100
Collateral Dependent Loans \| Commercial real estate ("CRE")
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment	66,000
Individually evaluated for impairment	17,400
Collateral Dependent Loans \| Multifamily residential and residential mixed-use
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for impairment	12,500
Individually evaluated for impairment	$ 2,600

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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 (g)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

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- 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

No definition available.

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- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ 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 (h)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

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