1. A system for converting unstructured documents into XML-compliant documents, said system comprising: a processor configured to execute instruction for performing the following operations: sectioning an unstructured document into tables containing text and blocks of text, the text comprising unstructured data, without tags identifying the data; receiving a user-selected portion of the unstructured document comprising the unstructured data; a parsing the user-selected section of the unstructured document automatically, without human intervention, to identify fact items and associated respective human-readable labels; comparing labels with a library of XBRL taxonomy concepts to associate one or more probable taxonomy concepts with each label; forwarding the fact items, labels, and respective probable associated taxonomy concepts to the user; receiving optional correction of associated possible taxonomy concepts, by the user, which may comprise new taxonomy concepts not originally in the library, selection of a correct concept from the probable concepts previously associated with a respective label or association of one or more previously associated labels with a different taxonomy concept from the library of XBRL taxonomy concepts; generating a structured XML-compliant document comprising the fact items, associated labels and associated concepts as XML tags; upon receipt of new XBRL taxonomy concepts from the user, generating an extension document for a taxonomy that contains the new concepts, wherein the XML-compliant document contains a reference to the extension document; and an interface that executes on a client computer to present the probable matching concepts associated with fact items and labels, and to enable the user to enter new concepts for inclusion in the extension document.