The salary of an American Doctor depends upon the speciality he has, with Paediatrics being at the bottom and Orthopaedics & Cardiology at the top. The lowest being around 205,000$ and the highest around 425,000$. If we take the mean income for all categories it should be around 300,000$ annually.
The average income of an American household is around 80000$ comparing this to the Doctors average income we can clearly see they earn much more than the average American.
Simply put a Doctor in America earns thrice/twice as much as an average American.Moreover if they have a working spouse the Income becomes even more.
So undoubtedly Doctors are richer than other Average Americans.