MCT (minimum connection time) at DTW for domestic to international DL-DL is 40 minutes.

Since both your inbound PHX-DTW and outbound DTW-AMS are DL mainline, I would say you'll likely have no trouble with this connection. Also, there are three or more flights DTW-AMS per day (you didn't mention your departure date) in the event of a disruption you might be able to catch the next DTW-AMS flight.