The Securities and Exchange Commission has posted the final version of its rule mandating Extensible Business Reporting Language for public companies.

The new XBRL rule requires public companies to begin filing their financial statements in an interactive data format that allows investors to download them more easily into spreadsheets and other types of software. The technology aims to make it easier for analysts to compare financial information across companies and industries. The SEC approved the new rule last December (see SEC Approves XBRL Mandate).

There will be a three-year phase-in of the new requirements. Companies with a worldwide float of over $5 billion as of the end of the second fiscal quarter of their most recently completed fiscal year will provide XBRL filings with their financial statements for fiscal periods ending on or after June 15, 2009. All other domestic and foreign large accelerated filers using U.S. generally accepted accounting principles will be subject to the same requirements the following year for fiscal periods ending on or after June 15, 2010.

Then all remaining filers using U.S. GAAP, including smaller reporting companies, and all foreign private issuers that prepare their financial statements in accordance with International Financial Reporting Standards, will need to file XBRL statements the following year for fiscal periods ending on or after June 15, 2011.

The XBRL mandate is part of the SEC’s planned move to an Interactive Data Electronic Applications, or IDEA, system to replace its old EDGAR system for storing and accessing financial filings.