XBRL-based structured digital financial reporting - Blog: Digital Financial Reporting (using XBRL)

Here is another demo of using the information the SEC is providing in XBRL.

Information about the public float of an SEC filer is provided in its XBRL filing, sometimes. I am not sure what the rules are about this. But, the RSS feed of the filings which I used yielded this information (these are best viewed in Microsoft Internet Explorer, Safari does not show the XML very well):

In HTML (Humans can read)
In HTML (Another approach to using HTML; used XML data islands, might require Microsoft Internet Explorer)
The XML (Computer can easily read)
The Stylesheet (used to change the XML into more readable HTML)

Basically, I used my Microsoft Access database to read the RSS feed. The RSS feed pointed to the filings. I read the filing information, grabbing the fact value for the concept "dei:EntityPublicFloat" where it existed. (Sometimes it did not exist, not sure what the reporting rules are).

There are various forms which can be used to make the information available (the bulleted list above). Some formats are easier for computers to read, some are easier for humans to read.

The more consistently the information is provided, the more useful the information. What is made available is determined by the rules an SEC filer has to follow.