Note 6 - Property and Equipment (Details) $ in Millions	Jan. 03, 2016 USD ($)
Property, Plant and Equipment [Abstract]
Estimated Cost to Complete Approved Projects and Current Construction in Progress	$ 13.1

An estimate of the costs to complete approved projects and construction in progress.

No definition available.

Name:	tile_EstimatedCostToCompleteApprovedProjectsAndCurrentConstructionInProgress
Namespace Prefix:	tile_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant