Specifications provide the fundamental technical definition of how XBRL works.  The main, current specification for XBRL is version 2.1, which can be seen on the Recommendations page. 

New specifications are developed from requirements statements.  They are initially discussed as "Working Groups Working Drafts" and "Internal Working Drafts" within the consortium and then released as "Public Working Drafts".  After a careful process of review which includes a "Last Call for Comments", they are then released as "Candidate Recommendations" and a "Call for Implementations" issued. At this point  in the process it is believed that a specification can be implemented and deployed in a manner similar to that of a 1.x version of a piece of software. A specification may stay at "Candidate Recommendation" status for a lengthy period of time while as many nuances and edge cases as possible are discovered and addressed.

Once sufficient implementation and deployment experience has been gathered and it is believed that no additional development of a specification is necessary, work is declared to be complete and it is finally released as an official XBRL Recommendation.  A Recommendation represents consensus within the XBRL International community and has its stamp of approval.  The International Steering Committee considers that the ideas or technology specified by a Recommendation are appropriate for widespread deployment to promote the mission of XBRL International.

The Technical Support Section provides supporting information on Specifications and other guidance on XBRL implementation.  It includes an explanation of the benefits of the latest version of the main Specification, 2.1.