Inconsistent tags between XBRL files from the SEC (EDGAR)

Question

I'm parsing every XBRL files from the SEC through EDGAR in order to retrieve some data (in json format on python).

I have no problem parsing those files. My problem lies in the structure of the XBRL files provided by the SEC, i noticed that some companies use some tags and others dont. Some will use "Revenues" while others won't have any tags pertaining to revenues, i have the same issue with "ShortTermBorrowings"...

Is there a list of XBRL tags from the SEC that are used throughout all companies ?

Thank's

Answer 1

The short answer is "no", there is not a list of required tags for financial reports made to the SEC (other than some "Document and Entity Information" metadata tags).

This reflects the nature of the underlying financial reports, which are governed by the US GAAP ("Generally Accepted Accounting Principles") accounting standard, which does not prescribe specific data points which must be reported, and as a result the XBRL system does not enforce specific required tags.

In both the examples that you've linked to where Revenue is not tagged, this appears to me to be poor tag choice. I think the best that you can do in this case is to infer that if RevenueNotFromContractWithCustomer is not also tagged, then Revenue == RevenueFromContractWithCustomerExcludingAssessedTax. Such inferences can be informed by the relationships in the US GAAP taxonmy. For example, see the definition of Revenue in the US GAAP taxonomy (and in particular, the "Relationships" tab).

Answer 2

Indeed, it is the case that filers use inconsistent tagging. This is one of the main challenges for processing XBRL data across filings.

There is a list of tags for use by all companies, in the US GAAP taxonomy namespace, however this alone is not enough to solve the problem, as (i) companies might still use different tags within this taxonomy, and (ii) companies can create new concepts in their own namespace, aka extension concepts, and sometimes do so even when a US GAAP concept would have been applicable.

But there is good news: Charles Hoffman, CPA solved this problem by providing a fundamental accounting concepts taxonomy, together with mappings and rules to make all filings interoperable. I recommend this tutorial as a starting point.

Answer 3

I would not rely solely on any list of tags the SEC or anyone else provides.

I'd also check the source data for the tags actually being used.

I'd also ask:

How can I create a list of all tags used throughout all SEC Edgar filings, for each "filing type" (10K, 10Q, Form 3, Form 4, Dorm 5, Form 13F, etc.)?