FINREP (FINancial REPorting, see http://www.eurofiling.info/) has published an XBRL architecture which is worth taking a look at if you are a student of XBRL and trying to figure out the best approach to use it. FINREP, which relates to financial reporting of financial institutions in Europe and uses International Financial Reporting Standards, is published by CEBS (Committee of European Banking Supervisors).
The architecture document can be found here. If you go to the EUROFILING home page (above) you can find additional information such as explanatory documentation, the draft taxonomy files (note that this is draft version).
CEBS has always been great about transparency of what they are doing, why, and the reasoning that has gone into what they are doing. The information they publish is intended for those participating in the COREP and FINREP projects, but this information is also very helpful to others who are making use of XBRL who have to grapple with similar issues. Why reinvent the wheel? Why not learn from what these regulators are spending vast amounts of resources to figure out?
In particular, this presentation is incredibly helpful. This is a PDF of a 325 page PowerPoint presentation! I would have hated to sit through that meeting. But, a tremendous amount of work was put into the slide deck. The presentation goes into detail about issues such as use of default dimensions, typed dimensions, and other things people don't tend to think about.
The bottom line here is that the FINREP architecture and other information is worth the effort to study. Other regulators, corporations, and consultants who help these folks can glean massive amounts of useful insight from what FINREP has made available. This architecture is not applicable to only financial reporting, it is applicable to FINREP in general. FINREP itself learned a lot from what COREP created. A next step the FINREP and COREP folks will go through is to reconcile the two different architectures, perhaps resulting in one architecture used for both FINREP and COREP.
Key aspects of the architecture include: