What version of InDesign? Did you install it properly or did you migrate from an old computer (something you should never do with Adobe applications)?
13.1 - InDesign CC
Fresh install, no migration at all
Are you running other apps along with this? With something as tricked out as your Mac Pro, it shouldn't have a slow down. But, I do know with my work iMac which is fairly new and has alot of RAM and all that, I have more slowdowns than I do with my 4 year old Macbook Pro that has less RAM, mainly because my work uses proprietary apps to where we pull files from and all that, which bogs things down, because the files we're working on themsevles are not actually on my computer, but in their cloud system. Its frustrating. But I hope we can find a solution for you.
No other open apps
There are a few background programs though, DropBox and LogMeIn.
Those are common to all other computers too though.