Delta flies there until the end of March direct from JFK on selected days. I forgot the details, but in general, you would leave DTW on Friday and connect to the GND flight which leaves JFK a little afer midnight (Sat) and arrives GND around 7 am. Return is Sat about 7:30 pm arriving JFK about 11 pm. Since DET is a Delta hub, you might even have a convenient connecting flight back home that night.
Fred
