Whichever library you're using (hole sizes may not be the same in other libraries!)
I didn't mean to imply that the hole sizes were documented. You have to go to the "device" and see which "package" it uses, and then edit the "package" and use the "info" command to look at the individual pads...
Actually, there may be an easier way. There is a "drilllegend.ulp" utility that will mark each sized hole with a unique symbol and create a nice little table. Type "run drilllegend" in the cli window, click "ok", let it run, turn of some layers so you can see what's there, and see if that is good enough...
The inconsistent libraries in general sorta suck. The Arduino reference design has some components with 0.91mm and some with 0.95mm holes, for example... (some MIGHT get filtered out when creating CNC drill files...)