Should be enough time. If the flight leaves PHX late, there is enough distance to make up some time in the air.
DTW is very easy to get from gate to gate. Even if the trams aren't running, you will have enough time to get to where you need to go.
If you are leaving from Terminal B or C, chances are it will be a smaller plane and you will have to gate check your carry on, particularly if you are heading to MKG. As it is around Christmas, most of the other PAX will be carrying larger or excess luggage.
I would book it.

Worse case scenario, you can rent a car and drive to MKG in about three hours rather than spend the night. If you do choose this option, communicate with DL to ensure the remaining leg won't be canceled.
Detroit has gotten a bum rap (yes, some of it is earned) but I have stayed overnight rather than drive home to GRR on late arrivals. Westin is the preferred choice. Easy access, good bar, great workout facility, attached to Terminal A.
Good luck!