Financial Instruments with Off-Balance-Sheet Risk and Concentrations of Credit Risk (Narrative) (Details) (USD $)	Dec. 31, 2013
Financial Instruments with Off-Balance-Sheet Risk And Concentrations Of Credit Risk [Abstract]
Standby letters of credit expire in 2014	$ 20,400,000
Standby letters of credit expire in 2015	1,900,000
Standby letters of credit expire in 2016	$ 150,000

Credit Commitment Amount Expire In Next Twelve Months

No definition available.

Name:	pfb_CreditCommitmentAmountExpireInNextTwelveMonths
Namespace Prefix:	pfb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant