Eiichi "Ed" Watanabe, an early evangelist for XBRL in Japan and globally, has set up a web site, XBRL House. This is how Watanabe-san describes his web site:
My intent of creating this website was to share what I have with respect to XBRL so that the information included would be of some value for those who join the XBRL world. I thought it would be good for me to do that because I was so involved in XBRL and I am retired almost from XBRL, although I am still an advisor of XBRL Japan.
One thing I would point out on the site is the library. I counted 20 books related to XBRL.
Stop by XBRL House and say hello to Ed!