Note 7 - Assets Held for Rent (Details Textual) - USD ($)	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Assets Held for Rent, Depreciation	$ 843,000	$ 896,000

The amount of depreciation expenses recognized for assets held for rent.

No definition available.

Name:	blfs_AssetsHeldForRentDepreciation
Namespace Prefix:	blfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration