Does it add up? Early evidence on the data quality of XBRL filings to the SEC

In 2009, the Securities and Exchange Commission rolled out the first stage of a multi-year program to transition its EDGAR disclosure repository to the XBRL format. The quality of the XBRL data in the repository is vital for the success of the Commission’s interactive data program. A key aspect of the data quality of these filings is the correctness of the mathematical relationships implied by the taxonomy and implemented in the instance document. One quarter of the filings by the initial 400 large corporations in the first round of submissions had errors, with differences reported monetary facts and the sum of other monetary facts that were bound together in a computation relationship. The primary cause of these errors was inappropriate treatment in the instance documents of underlying debit/credit assumptions in the taxonomy. The results of the research have a number of implications for filers, the SEC, XBRL US, software vendors and the global XBRL community.