DEPOSITS - Scheduled Maturities of Time Deposits (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Certificates of deposit of $250,000 or less
2023	$ 664,365
2024	105,126
2025	22,085
2026	753
2027	711
Total	793,040	$ 285,768
Certificates of deposit of more than $250,000
2023	355,138
2024	39,375
2025	636
2026	394
2027	838
Total	396,381	220,950
Total certificates of deposit
2023	1,019,503
2024	144,501
2025	22,721
2026	1,147
2027	1,549
Total	1,189,421
Deposits	$ 179	$ 602

Contractual Maturities, Time Deposits, $250,000 Or More [Abstract]

No definition available.

Name:	banc_ContractualMaturitiesTimeDeposits250000OrMoreAbstract
Namespace Prefix:	banc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Time Deposit Maturities Year Five And Thereafter

+ References

No definition available.

+ Details

Name:	banc_TimeDepositMaturitiesYearFiveAndThereafter
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits $250,000 Maturities or More, Year Five and Thereafter

+ References

No definition available.

+ Details

Name:	banc_TimeDeposits250000MaturitiesOrMoreYearFiveAndThereafter
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits $250,000 Maturities or More, Year Four

+ References

No definition available.

+ Details

Name:	banc_TimeDeposits250000MaturitiesOrMoreYearFour
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits $250,000 Maturities or More, Year One

+ References

No definition available.

+ Details

Name:	banc_TimeDeposits250000MaturitiesOrMoreYearOne
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits $250,000 Maturities or More, Year Three

+ References

No definition available.

+ Details

Name:	banc_TimeDeposits250000MaturitiesOrMoreYearThree
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits $250,000 Maturities or More, Year Two

+ References

No definition available.

+ Details

Name:	banc_TimeDeposits250000MaturitiesOrMoreYearTwo
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits, $250,000 Or More

+ References

No definition available.

+ Details

Name:	banc_TimeDeposits250000OrMore
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits, Less than $250,000

+ References

No definition available.

+ Details

Name:	banc_TimeDepositsLessthan250000
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits Under $250,000 Maturities [Abstract]

+ References

No definition available.

+ Details

Name:	banc_TimeDepositsUnder250000MaturitiesAbstract
Namespace Prefix:	banc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Time Deposits Under $100,000 Maturities, Year Five and Thereafter

+ References

No definition available.

+ Details

Name:	banc_TimeDepositsUnder250000MaturitiesYearFiveAndThereafter
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits Under $250,000 Maturities, Year Four

+ References

No definition available.

+ Details

Name:	banc_TimeDepositsUnder250000MaturitiesYearFour
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits Under $250,000 Maturities, Year One

+ References

No definition available.

+ Details

Name:	banc_TimeDepositsUnder250000MaturitiesYearOne
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits Under $250,000 Maturities, Year Three

+ References

No definition available.

+ Details

Name:	banc_TimeDepositsUnder250000MaturitiesYearThree
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Time Deposits Under $250,000 Maturities, Year Two

+ References

No definition available.

+ Details

Name:	banc_TimeDepositsUnder250000MaturitiesYearTwo
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Total Certificates Of Deposit [Abstract]

+ References

No definition available.

+ Details

Name:	banc_TotalCertificatesOfDepositAbstract
Namespace Prefix:	banc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of addition (reduction) to the amount at which a liability could be incurred (settled) in a current transaction between willing parties.

+ References

No definition available.

+ Details

Name:	us-gaap_LiabilitiesFairValueAdjustment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of time deposit maturing in fourth fiscal year following current fiscal year. Time deposit includes, but is not limited to, certificate of deposit. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601

+ Details

Name:	us-gaap_TimeDepositMaturitiesYearFour
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of time deposit maturing in next fiscal year following current fiscal year. Time deposit includes, but is not limited to, certificate of deposit. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

Name:	us-gaap_TimeDepositMaturitiesYearOne
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of time deposit maturing in third fiscal year following current fiscal year. Time deposit includes, but is not limited to, certificate of deposit. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

Name:	us-gaap_TimeDepositMaturitiesYearThree
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of time deposit maturing in second fiscal year following current fiscal year. Time deposit includes, but is not limited to, certificate of deposit. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

Name:	us-gaap_TimeDepositMaturitiesYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of time deposit liabilities, including certificates of deposit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=116652737&loc=d3e64164-112818

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 210.9-03.12)
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

+ Details

Name:	us-gaap_TimeDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant