Note 4 - Warranty Reserves (Details)	9 Months Ended
Sep. 30, 2014
Product Warranties Disclosures [Abstract]
Product Warranty Period for Sold Equipment	1 year

Represents the product warranty period granted by the entity on new equipment sold.

No definition available.

Name:	btn_ProductWarrantyPeriodForSoldEquipment
Namespace Prefix:	btn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration