The US Securities and Exchange Commission has an interesting page on their site setting out a number of documents regarding the Voluntary program. The page also includes links to videos of remarks by Chairman Cox at XBRL conferences in San Jose and Tokyo. Spotlight on Tagged Data and XBRL Initiatives for EDGAR Filings

There's support for XBRL out there. This article indicates a couple of the reasons why. Washington and Wall Street, published by Institutional Risk Analytics - XBRL Commentary Page

Here's a great calendar of XBRL events that has been posted on the XBRL US site. http://xbrl.org/us/calendar/

The Bank of Japan has gone live with XBRL, using it for receiving filings from 500 banks in the country. Financial and Payment System

This paper from the FFEIC of the US, one of the leading adopters of XBRL for regulatory purposes, is an interesting one that shows how business processes can be improved through the use of XBRL to gather and report data.
http://xbrl.org/us/us/FFIEC%20White%20Paper%2031Jan06.pdf

The call for papers is out for the 6th XBRL Conference at Bryant University to be held June 8-9, 2006 xbrl