The S.E.C., the American regulator body, is in the process of making the filing of financial reports completely XBRL based for large companies in the U.S.
Already now the SEC offers companies the opportunity to partake in a voluntary XBRL effort, for which they provide a GAAP accountancy based Taxonomy. Companies like Ford, General Electric, IBM, Pepsi, United Technologies are already filing their reports in the XBRL format, on a voluntary base.
Most likely, from December 2008 on, large corporations of over 5$ billion total float will be obliged to file their reports in the XBRL standard.
SEC to mandate filing in XBRL
XBRL US Supports SEC's Unanimous Recommendation to Mandate XBRL