You can't get much more detailed than NN/G or Spool's conferences, IMHO. I find the latter typically the best available throughout the country.
Confab looks great, though note it's about content strategy--not UX (though I tend to argue content is very much UX, but others disagree...)
If you are in MSP, you may also want to look into MIMA's annual summit event: http://www.mima.org/
While not UX specific, it covers a lot of the same ground, as well as content strategy, marketing and the like.
UofM usually has a conference or two during the year that you may want to keep an eye on.
And, finally, the Twin Cities have a long tradition of very well attended BarCamp conferences every year. Again, not UX-only, but typically quite well organized and free--so can't complain about the cost at all. ;)