Loans And Leases Receivable, Number Of Letters Of Credit Outstanding, Related Party

No definition available.

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Namespace Prefix:	banc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Related Party Transaction, Legal Services, Period

+ References

No definition available.

+ Details

Name:	banc_RelatedPartyTransactionLegalServicesPeriod
Namespace Prefix:	banc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts due from related parties at the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(e))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

Name:	us-gaap_LoansAndLeasesReceivableRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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

- 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.

+ Details

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Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=banc_EntityAffiliatedWithFormerPresidentAndChiefExecutiveOfficerMember
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Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=banc_LegalFeesAndCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=banc_ReimbursementOfLegalDisputeMember
Namespace Prefix:
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RELATED-PARTY TRANSACTIONS - Legal Fees and Other Matters (Details)		3 Months Ended	9 Months Ended	12 Months Ended
	Apr. 06, 2015 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($) letter_of_credit	Dec. 31, 2017 USD ($) letter_of_credit
Related Party Transaction [Line Items]
Expenses from transactions with related parties	$ 263,000
Entity Affiliated With Former President And Chief Executive Officer \| Legal Fees And Credit
Related Party Transaction [Line Items]
Legal services period (more than four months)				4 months
Expenses from transactions with related parties		$ 330,000	$ 0
Number of letters of credit outstanding \| letter_of_credit			3	3
Committed line of credit			$ 0	$ 0
Entity Affiliated With Former President And Chief Executive Officer \| Reimbursement Of Legal Dispute
Related Party Transaction [Line Items]
Expenses from transactions with related parties		$ 100,000