I completed this implementation and have tested on 5 10Ks for Caterpillar going from 2015 back to 2010. Problems occur when I go back further due to the nature of the XBRL definition.

The facts have a unique name which is supposed to be standard us-gaap:CurrentAssets for example. Going back to 2010 this is the case but before then it appears for have been us-gaap:AssetsCurrent. Not sure how I will get around this… maybe there is some sort of mapping.

Merging XBRL facts across periods