JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES - Schedule of Trusts (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Amount	$ 61,857	$ 61,857
Trust Preferred Securities Subject to Mandatory Redemption \| Luther Burbank Statutory Trust I \| Trusts
Debt Instrument [Line Items]
Amount	$ 41,238	$ 41,238
Rate	1.63%	3.27%
Trust Preferred Securities Subject to Mandatory Redemption \| Luther Burbank Statutory Trust I \| Trusts \| LIBOR
Debt Instrument [Line Items]
Rate Index (Quarterly Reset)	1.38%
Trust Preferred Securities Subject to Mandatory Redemption \| Luther Burbank Statutory Trust II \| Trusts
Debt Instrument [Line Items]
Amount	$ 20,619	$ 20,619
Rate	1.87%	3.51%
Trust Preferred Securities Subject to Mandatory Redemption \| Luther Burbank Statutory Trust II \| Trusts \| LIBOR
Debt Instrument [Line Items]
Rate Index (Quarterly Reset)	1.62%

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6036836-161870

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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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

Including the current and noncurrent portions, the carrying value of junior subordinated long-term debt owed to unconsolidated subsidiary trusts as of the balance sheet date. Such debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets and was initially scheduled to be repaid after one year or beyond the normal operating cycle if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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