I've just released to CPAN the first version of a module to parse XBRL. While it is still immature interms of functionality, my plan is to accrete functionality in subsequent versions until it is standards compliant and fully functional. At the moment it can parse the document and make the components (e.g. items, contexts, elements, linkbases) available as well as generate a very, very basic HTML version. The module is available here and the project is hosted on Github here.