XBRL Functions for XSLT
Functions defined in the XBRL function registry can be called from within an XSLT context for transforming XBRL instance documents. These XBRL functions are defined in one of two namespaces:
http://www.xbrl.org/2008/function/instance (usually used with the xfi: prefix)
http://www.xbrl.org/2010/function/formula (usually used with the xff: prefix)
So the XBRL function xfi:context, for example, expands to http://www.xbrl.org/2008/function/instance:context (assuming this namespace has been bound to the xfi: prefix).
For a complete list of the functions, go to http://www.xbrl.org/functionregistry/functionregistry.xml.