XBRL reports in SEC database are the same quarterly and annual reports filed by the company using traditional process before. Meaning, these are the audited financial statements of the companies, which were just translated into XBRL format by assigning each values with XBRL tag. However, translating process and the resulted XBRL reports are not yet required to be audited by an independent firm or professional.
It may be possible to have errors upon filing. So, XBRLAnalyst already designed various ways to easily detect reporting errors, which are listed and discussed in this article.