XML 43 R71.htm IDEA: XBRL DOCUMENT v2.4.1.9
LOANS AND LEASES AND ALLOWANCE FOR LOAN AND LEASE LOSSES - Non Traditional Mortgage Performance Loan to Value Ratio (Detail) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended 0 Months Ended
Mar. 31, 2015
Loan
Dec. 31, 2014
Loan
Mar. 31, 2015
Loan
Dec. 31, 2014
Loan
Mar. 31, 2014
Financing Receivable, Recorded Investment [Line Items]          
Amount $ 3,933,715us-gaap_LoansAndLeasesReceivableGrossCarryingAmount $ 3,949,122us-gaap_LoansAndLeasesReceivableGrossCarryingAmount $ 3,933,715us-gaap_LoansAndLeasesReceivableGrossCarryingAmount $ 3,949,122us-gaap_LoansAndLeasesReceivableGrossCarryingAmount $ 2,396,995us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
Non-Traditional Mortgages (NTM)          
Financing Receivable, Recorded Investment [Line Items]          
Count 402us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember		 407us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember		      
Amount 353,825us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember		 350,575us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember		 353,825us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember		 350,575us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember		  
Non-Traditional Mortgages (NTM) | Green Loans          
Financing Receivable, Recorded Investment [Line Items]          
Amount 124,700us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 128,200us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 124,700us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 128,200us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		  
Non-Traditional Mortgages (NTM) | Interest Only Loans          
Financing Receivable, Recorded Investment [Line Items]          
Amount 216,900us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 209,300us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 216,900us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 209,300us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		  
Non-Traditional Mortgages (NTM) | Negative amortization          
Financing Receivable, Recorded Investment [Line Items]          
Amount 12,200us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 13,100us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 12,200us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 13,100us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		  
Non-Traditional Mortgages (NTM) | First lien          
Financing Receivable, Recorded Investment [Line Items]          
Count 382us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 387us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Amount 348,964us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 345,483us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 348,964us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 345,483us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		  
Non-Traditional Mortgages (NTM) | First lien | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Non-Traditional Mortgages (NTM) | First lien | Green Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 147us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 148us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 147us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 148us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		  
Amount 119,958us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 123,177us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 119,958us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 123,177us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | Interest Only Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 204us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 207us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Amount 216,765us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 209,207us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 216,765us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 209,207us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | Negative amortization          
Financing Receivable, Recorded Investment [Line Items]          
Count 31us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 32us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		      
Amount 12,241us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 13,099us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 12,241us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 13,099us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 100.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | Less than 61          
Financing Receivable, Recorded Investment [Line Items]          
Count 152us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 152us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Amount 161,248us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 158,133us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 161,248us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 158,133us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		  
Non-Traditional Mortgages (NTM) | First lien | Less than 61 | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 46.20%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 45.80%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Non-Traditional Mortgages (NTM) | First lien | Less than 61 | Green Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 77us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 77us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		      
Amount 56,136us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 58,856us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 56,136us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 58,856us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | Less than 61 | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 46.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 47.80%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | Less than 61 | Interest Only Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 60us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 60us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Amount 99,152us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 93,254us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 99,152us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 93,254us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | Less than 61 | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 45.80%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 44.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | Less than 61 | Negative amortization          
Financing Receivable, Recorded Investment [Line Items]          
Count 15us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 15us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		      
Amount 5,960us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 6,023us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 5,960us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 6,023us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | Less than 61 | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 48.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 46.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessThanSixtyOnePercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | 61-80          
Financing Receivable, Recorded Investment [Line Items]          
Count 109us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 111us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Amount 134,921us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 133,550us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 134,921us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 133,550us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		  
Non-Traditional Mortgages (NTM) | First lien | 61-80 | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 38.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 38.60%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Non-Traditional Mortgages (NTM) | First lien | 61-80 | Green Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 45us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 45us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		      
Amount 46,129us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 46,177us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 46,129us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 46,177us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | 61-80 | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 38.50%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 37.50%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | 61-80 | Interest Only Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 52us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 54us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Amount 83,480us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 81,472us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 83,480us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 81,472us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | 61-80 | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 38.50%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 38.90%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | 61-80 | Negative amortization          
Financing Receivable, Recorded Investment [Line Items]          
Count 12us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 12us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		      
Amount 5,312us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 5,901us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 5,312us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 5,901us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | 61-80 | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 43.40%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 45.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueSixtyOnetoEightyPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | 81-100          
Financing Receivable, Recorded Investment [Line Items]          
Count 54us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 55us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Amount 27,875us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 27,554us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 27,875us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 27,554us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		  
Non-Traditional Mortgages (NTM) | First lien | 81-100 | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 8.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 8.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Non-Traditional Mortgages (NTM) | First lien | 81-100 | Green Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 18us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 18us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		      
Amount 11,833us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 11,846us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 11,833us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 11,846us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | 81-100 | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 9.90%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 9.60%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | 81-100 | Interest Only Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 33us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 33us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Amount 15,463us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 14,927us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 15,463us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 14,927us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | 81-100 | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 7.10%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 7.10%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | 81-100 | Negative amortization          
Financing Receivable, Recorded Investment [Line Items]          
Count 3us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 4us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		      
Amount 579us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 781us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 579us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 781us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | 81-100 | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 4.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 6.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueEightyOnetoOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | Greater than 100          
Financing Receivable, Recorded Investment [Line Items]          
Count 67us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 69us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Amount 24,920us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 26,246us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 24,920us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 26,246us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		  
Non-Traditional Mortgages (NTM) | First lien | Greater than 100 | Loan Portfolio Concentration Risk | Nontraditional First Lien Mortgage Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 7.10%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		 7.60%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NontraditionalFirstLienMortgageLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember		      
Non-Traditional Mortgages (NTM) | First lien | Greater than 100 | Green Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 7us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 8us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		      
Amount 5,860us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 6,298us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 5,860us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 6,298us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | Greater than 100 | Green Loans | Loan Portfolio Concentration Risk | Green Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 4.90%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		 5.10%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_GreenLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_GreenLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | Greater than 100 | Interest Only Loans          
Financing Receivable, Recorded Investment [Line Items]          
Count 59us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 60us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Amount 18,670us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 19,554us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 18,670us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 19,554us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | Greater than 100 | Interest Only Loans | Loan Portfolio Concentration Risk | Interest Only Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 8.60%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		 9.30%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_InterestOnlyLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_InterestOnlyLoansMember		      
Non-Traditional Mortgages (NTM) | First lien | Greater than 100 | Negative amortization          
Financing Receivable, Recorded Investment [Line Items]          
Count 1us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 1us-gaap_MortgageLoansOnRealEstateNumberOfLoans
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		      
Amount $ 390us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 $ 394us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 $ 390us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 $ 394us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		  
Non-Traditional Mortgages (NTM) | First lien | Greater than 100 | Negative amortization | Loan Portfolio Concentration Risk | Negative Amortization Loans Portfolio          
Financing Receivable, Recorded Investment [Line Items]          
Concentration risk percentage 3.20%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember		 3.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= banc_NegativeAmortizationLoansPortfolioMember
/ us-gaap_ConcentrationRiskByTypeAxis
= banc_LoanPortfolioConcentrationRiskMember
/ banc_FinancingReceivablePortfolioSegmentAxis
= banc_NonTraditionalMortgagesLoanMember
/ banc_LoantoValueAxis
= banc_LoantoValueLessthanOneHundredPercentMember
/ us-gaap_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis
= us-gaap_FirstMortgageMember
/ us-gaap_ProductOrServiceAxis
= banc_NegativeAmortizationLoansMember