SYNOPSIS eXtensible Business Reporting Language (XBRL) has the potential to improve the transparency of financial reports; however, its complexity creates the risk of introducing errors that are a threat to its usefulness. XBRL is a complex technological change in financial reporting of nearly unprecedented scope. Prior to June 2009, the date of the first mandated XBRL filings, the SEC made available a Voluntary Filing Program (VFP) to assist in addressing the difficulties of creating XBRL documents. This study examines errors in the VFP filings, and investigates whether stakeholders used their experience to improve the XBRL technology and processes. Findings indicate a reduction in errors over time, suggesting that the VFP for XBRL was successful. These results support the use of a VFP to identify and solve unanticipated issues and evaluate the feasibility of implementing large-scale technological changes in financial reporting and perhaps comprehensive changes in accounting standards such as the implementation of International Financial Reporting Standards.