Have you tried the Users - Courses report? That should give you all the details you need.

I have. I have a customer that wants one line with a summarized number of courses and completion percentage, but in the Users - Courses report it lists each course on a separate line. 

Oh so you just need roll by course not user? If yes, then you can use the report called, Courses - Users it shows 1 line per course with stats for each course across the columns.

This report is better! Is there a way though that I can set it up to be able to drill down and see the specific users? Ideally they want to know which users are in each status.

this report is only a roll up..the details version is the report called, Users - Courses.