Hi dblake2 and finalbegining,
You're both right, there should be a setting for this. In case you had previously been going to File > Layout to turn off the preview pane however, let me remind you that there's a quick toggle button just above the preview pane itself in every window, between the blue question mark and 'Change your view' buttons. That is the fastest way to see what's behind the preview pane in Details view.
Windows Outreach Team