The folks at OpenFilinghave made a couple of very useful resources available for those who are serious about learning how to model business information using XBRL.
The first is a video which shows, in detail, an approach used by FINREP to modeling information. The video titled FINREP 2012 taxonomy and the Data Modeler - ExcelXbrlGen (Excel add in) is 1 hour and 26 minutes long, but there are some good nuggets of information. It is worth the time for those who are serious.
The second is the Excel add in discussed in the video, Data Modeler: ExcelXbrlGen (Excel add in). The Excel add in appears to be written in .Net, is open source, and is described as follows:
Developed in order to facilitate creation of taxonomies according to the draft Eurofiling architecture out of the Data Points Model (DPM) in MS Excel format automatic creation of primary items, dimensions, domains (structures of members) taxonomies consisting of schema files and linkbases (label and definition) out of the Excel DPM interface for definition and output of tables linkbase (according to Eurofiling draft rendering schema and algorithms)
While you may not need to create taxonomies according to the Eurofiling architecture, this is a great reverse-engineering opportunity and it helps you see an approach used by others in working with XBRL.