When your iXBRL file is created, it is equipped with a hashcode (or a hash total). Thus, every single time you convert your files (Excel template + PDF annual report), a new hashcode is generated. That way, it functions like a guarantee that your file remains untampered after it has been audited.
When you open your file in the ParsePort XBRL Inspector, you can find the hashcode in the Validation pane under "General Information", but if you scroll down to the "Zip Content" section you will see that many of the folders contained in your zip-package are equipped with their own hashcode. These codes serve the same function, which shows that each of these files remain untampered.