Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Statement of Cash Flows [Abstract]
Transfer of loans receivable to loans held for, transfer from allowance for loan and lease losses	$ 0	$ 0

Transfer of Portfolio Loans and Leases to Held-for-sale, Allowance

No definition available.

Name:	banc_TransferofPortfolioLoansandLeasestoHeldforsaleAllowance
Namespace Prefix:	banc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration