COMMITMENTS AND CONTINGENCIES (Details 2) (Shareholder derivative action)	0 Months Ended
Sep. 24, 2012 item
Shareholder derivative action
COMMITMENTS AND CONTINGENCIES
Number of cases consolidated	2

Represents the number of cases that were consolidated.

No definition available.

Name:	bpax_NumberOfCasesConsolidated
Namespace Prefix:	bpax_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration