XBRL Footnote Requirements
EFM 6.6.40 describes where “texts that are shown in the HTML/ASCII document at the bottom of a page on the face of the financials preceded by distinct superscripts must appear in the corresponding instance.”
SEC Staff Interpretations and FAQs Question F.3 answer the question of application of these footnotes outside the face financials by saying “including the superscripted text at the bottom of a footnote table in an XBRL Footnote link is optional.”
Therefore XBRL Footnotes are required to be applied on the face statements but are optional within the notes to the financial statements.
How to Apply XBRL Footnotes
In order to apply XBRL Footnotes to a fact the first step is to define the XBRL Footnote. To do that, highlight the text of the footnote excluding the footnote identifier (in this case (1)).
Then click the Footnote button from the XBRL Menu Bar and provide the XBRL Footnote with a label that you will recognize and click Apply.
To apply the previously created XBRL Footnote to the corresponding XBRL Fact in the table, click on one or both of those facts together and from within the XBRL Fact Properties panel click Add/Remove Footnotes in the bottom right of the panel.
Then from the XBRL Footnotes panel click, drag, and drop the appropriate XBRL Footnote from the list of all the XBRL Footnotes in the document on the left to the Applied XBRL Footnotes on the right.
After the applicable XBRL Footnotes have been moved over to the Applied box, close this window and then click the green checkmark in the XBRL Fact Properties panel to apply the XBRL Footnote.
Once your changes have been made, the selected and applied footnote is visible in the XBRL Fact Properties panel. Also a number is now visible in the cell where the XBRL Footnote was applied. This number represents the actual number of XBRL Footnotes applied to that fact. It does not correspond to the document footnote identifier.