Fairly early in the evolution of XBRL I started collecting "patterns". These patterns have gone through numerous versions and terms, but I think that I am now settling on a more precise set of terminology and an improved set of examples.
All the things in say an SEC XBRL financial filing are not the same. Many people refer to all of these things erroneously as "tags". The more proper term is perhaps report element, the things which make up an SEC XBRL financial report. All of the report elements can be grouped into a finite set of categories: network, [Table], [Axis], [Member], [Line Items], Concept, [Abstract]. (i.e. they are not random)
These report elements are related to other report elements in specific ways. For example, a [Table] is made up of one or more [Axis] and exactly one set of [Line Items]. Understanding which category of report elements relates to other category(s) of report elements and how is (a) helpful to creating SEC XBRL financial reports which are logical and sensible and (b) is something which can be leveraged by software.
These relations have patterns. I used to group all of these patterns together calling them sometimes simply "Patterns" or "Metapatterns" or "Information Models". My thinking on this has changed based on maturing ideas and very good input from others. Here are my new terms and updated sets of examples which explain these relationship patterns:
- Accounting Concept Arrangement Patterns: What I used to call "metapatterns" or "information models" are really better called accounting concept arrangement patterns or [Line Items] arrangement patterns. That is what they are: how the concepts within a set of [Line Items] are arranged or organized. Could be a roll up, roll forward, hierarchy, adjustment, variance, some complex computation, etc.
- Member Arrangement Patterns: What I used to call "member aggregation models" is really better called a member arrangement pattern because these patterns describe how the [Member]s or an [Axis] are arranged.
- Report Component Arrangement Patterns: What I used to call "flow models" is better called report component arrangement patterns because what they do is describe how the components which make up a report are organized or sequenced.
I am not totally sure that everything in each group is actually a pattern of that group. Further, I am not totally sure that I have accumulated every possible pattern for financial reporting. What I can tell you with certainty is that (a) these relations are NOT random and (b) computer software can leverage these patterns.
There are three other things which are helpful in using this information:
- Business Use Cases: These are basically a set of business use cases which I have distilled from financial reports and financial report taxonomies over the years. Both IFRS and US GAAP financial reports are covered. What these do is let you focus on the nuances of working with digital financial reports. These business use cases are small, focused, and well documented.
- Comprehensive Example: The components of a financial report do not exist in isolation, they can many times relate to other components. For example, a balance sheet intersects with the statement of changes in equity in that the facts which represent the beginning balance and ending balance of each equity account appears in both report components. The comprehensive example helps sees these intersections. The comprehensive example helps you understand these intersections and understand how one pattern must be created so that it properly intersects with other report components.
- Reference Implementation(of an SEC XBRL Financial Report): While all of the previous examples where general and not relating directly to the US GAAP or IFRS taxonomies, this reference implementation is a high-quality example of an SEC XBRL financial filing. [NOTE: This is a work in progress currently as software vendors update their products to support the 2013 US GAAP Taxonomy]
While documentation of all this information is provided for each set of patterns or examples, you can get the complete set of information on the Digital Financial Reporting page. As it is becoming increasingly clear that digital financial reporting will be part of our future, it is increasingly important that accountants understand the nuances of using technologies such as XBRL.