SELF-INSURANCE (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011
SELF-INSURANCE [Abstract]
Self insurance exposure for individual claims	$ 60
Minimum annual aggregate attachment point	2,072
Self-insured employee health plan expenses	$ 1,231	$ 1,089

Represents the employer's minimum overall limit of claim liability, which is adjusted based on the size of the group insured, as of the balance sheet date.

No definition available.

Name:	basi_AnnualAggregateAttachmentPointMinimum
Namespace Prefix:	basi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant