I am flying LGA-DTW-LAS and I am carrying two huge suitcases that I do not want in LAS (I'd rather drop them off with my family in DTW during the stopover) for my time there. Is it possible to check your bags in only for the first leg of your two-legged flight?

Maybe I just should have called NW for this, but you guys are always pretty knowledgable and I was curious what other airlines do