In an effort to help accountants understand what a quality SEC XBRL financial filing looks like and how to differentiate quality filing from a marginal or even poor quality filing, I have put together a number of resources.
Documentation of characteristics
First, this document provides a summary of characteristics and some details which helps one see how to evaluate quality. These characteristics seem hard to dispute. The list may not yet be comprehensive, but I believe that it is a step in the right direction. Here is a list of the high level characteristics:
Prototype battery of validation reports
Second, in support of those characteristics and to help better understand the characteristics, I created a battery of validation reports. You can get to this prototype here. Look closely at this prototype, there is really a lot to see. Notice that the reports are relevant to proving the characteristics listed above.
Model/Reference implementation
Third, I have been nurturing along a model or reference implementation of an SEC XBRL financial filing. This is the latest instantiation of that model. While the model is not a large SEC XBRL financial filing, it does cover all the bases. It is this filing which is being validated using the battery of validation reports above.
Education
Finally, if you don't understand what you are looking at, you really can't possibly judge good from bad. This web page contains the document Understanding SEC XBRL Financial Filings. It provides a solid framework for and details needed to grasp XBRL. It does not provide everything you need, but it certainly provides a solid foundation upon which to build.