General (Details)	Mar. 31, 2013
General [Abstract]
Threshold limit for likelihood events (in hundredths)	50.00%

Refers to threshold limit for likelihood events in percentage.

No definition available.

Name:	fbss_ThresholdLimitForLikelihoodEvents
Namespace Prefix:	fbss_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant