Complex sentence: In the 2011--12 season, it was the highest rated, most watched TV program in Nielsen ratings, beating "American Idol", which had previously been the most watched TV program for eight consecutive seasons and eight straight years.
Split into simpler sentences: In the 2011--12 season, it was named the highest rated, most watched TV program in Nielsen ratings. In second place was "American Idol", a show that had previously held the title of most watched TV program for eight consecutive seasons and eight straight years.