SELF-INSURANCE (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Self insurance exposure for individual claims			$ 75
Minimum annual aggregate attachment point			$ 85
Self-insured employee health plan expenses	$ 1,026
Self Insured Expenses		$ 925

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