Summary of Activities in Reserve for Loss Reimbursements on Sold Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
Summary of activity in reserve for loss reimbursements on sold loans [Line Items]
Balance at beginning of period	$ 5,427	$ 3,485
Provision for loan repurchases	571	256
Payments made for loss reimbursement on sold loans	(132)	(243)
Balance at end of period	$ 5,866	$ 3,498

Provision charged for the period based on estimated losses for sold loans that may have to be subsequently repurchased and amounts that may have to be paid to reimburse certain investor losses due to defects that occurred in the origination of the loans.

No definition available.

Name:	banc_ProvisionForLossReimbursementsOnSoldLoans
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration