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

The document Core Financial Reporting Semantics points out the key financial reporting semantics which I see in a balance sheet, income statement, cash flow statement, and overview of information about how a company reports its financial information.

All of these core financial reporting semantics are supported, and in fact determined by, a set of 5525 SEC XBRL financial filings which I examined. You can find the complete data set here.

Jean Louis Rodolpe Agassiz is attributed with the following quote:

The facts will eventually test all our theories, and they form, after all, the only impartial jury to which we can appeal.

The following is a summary of the core semantics which SEC XBRL filings show. SEC XBRL financial filings would find it hard to justify not following these core financial reporting semantics in my view:

Balance sheets report assets.
Balance sheets report liabilities and equity.
Balance sheets report equity.
Balance sheets balance.
Cash flow statements report net cash flow.
Net cash flow foots (perhaps in two ways, perhaps only in one).
Income statements report net income (loss).
OPTIONAL, certainly a best practice: Income statements report income (loss) from continuing operations before taxes.
OPTIONAL, certain industries do not apply: Balance sheets report current assets and current liabilities.

Are their other rules? Likely. Those 9 rules would be very, very hard to dispute.

While the US GAAP Taxonomy can be ambiguous about how this information is reported, it is the case, as proven by SEC XBRL financial filings themselves, that this information must be reported it seems to me. The US GAAP taxonomy does have concepts for every one of these 9 rules. As such, an SEC filer would be hard pressed to justify creating an extension concept for any of these items, it seems to me.