Digital Financial Reporting

As a by-product of something else I was working on I have some observations relating to the use of [Axis] in the US GAAP Taxonomy. You can grab the information I summarize here.  The following is a summary of some observations/questions which I have:

• Three different sets of [Axis] for Other Comprehensive Income (Loss), Net of Tax.  Why is it that Other Comprehensive Income (Loss), Net of Tax is modeled in three different areas of the US GAAP Taxonomy with three different sets of [Axis]? Why would how something is modeled change based on where in the taxonomy that it is modeled?
• Balance sheet line items and possible line items in disclosures not in sync. Why is it that the balance sheet is modeled as a [Table], yet line items which could go on the balance sheet as line items and would certainly tie to the balance sheet are not modeled as a [Table]? Seems logical that each of these list of detailed items would have the same [Axis] as the balance sheet if they are modeled as concept.  (If they were modeled as dimensions of a concept I can see why the [Axis] would be different.)
• [Table Text Block] go inside or outside a [Table]. Why is it that the same information is outside a table if it is [Table Text Block] tagged (block tagged), yet if that exact same information is detailed tagged, then it is modeled within a [Table]? It seems to me that whether something is "block tagged" or "detailed tagged", it still relates to the [Table]. The only difference is whether one tag is provided (i.e. for block tagged) or multiple tags are provided (i.e. for detailed tagged) for the information relating to that [Table].
• Class of stock [Axis] different on balance sheet and in disclosures. Why is it that common stock and preferred stock modeled on the balance sheet has different [Axis] than the same information modeled in the disclosures? The disclosure for class of stock information makes more sense than that information as it exists on the balance sheet.  Also, it seems to me that it would be more appropriate to have "Class of Preferred Stock [Axis]" and "Class of Common Stock [Axis]" and separate the disclosure into two disclosures, rather than putting two different things together. Treasury stock I am not sure about, I need to research some things.

Basically, I would advise caution when it comes to figuring out which [Axis] to use in SEC XBRL filings.  These sorts of inconsistencies point out that how the US GAAP Taxonomy is modeled might not offer good guidance.

It simply cannot be the case that where in the taxonomy that something is modeled (i.e. in which network) has anything to do with what [Axis] are assigned to the [Table] or whether something should be modeled as a [Table].  The way I see it, this provides additional information that everything within the US GAAP Taxonomy should be modeled as an explicit [Table].

Check out my details and go look at the 2011 US GAAP taxonomy (commercial and industrial companies entry point) for yourself.  I would be interested in the conclusions which you reach.