The document provides an overview of eXtensible Business Reporting Language (XBRL), including what it is, how it works, key terms, SEC filing requirements, best practices for tagging financial documents in XBRL format, and the process and deliverables for outsourcing XBRL filing services. XBRL creates standardized, machine-readable tags for financial disclosures to facilitate analysis and reuse of reported information. Companies must file various financial reports in XBRL format according to SEC phase-in schedules.