The SEC sent out a friendly letter to filers. The letter included this statement:
Acceptance of your filing by EDGAR does not mean that your filing is complete or in compliance with the Commission's requirements.
Given that providing proper calculation relations for roll ups is only one of many, many things necessary to make sure an SEC XBRL financial filing is correct, I would suspect that the SEC will be sending more friendly letters.
In addition, the SEC provided this Staff Observations which was basically complaining about the use of extension concepts, particularly by small filers.
For those who want to proactively get their ducks in a row, this document, Digital Financial Reporting Principles, will keep you ahead of your competitors.
"Quality means doing it right when no one is looking." - Henry Ford.