Complex sentence: He appeared less often in his last couple of years with the show, and eventually left the series to star on "Detroit 1-8-7", but returned to the show starting in the 19th season.
Split into simpler sentences: He appeared less often in his last couple of years with the show, and eventually left the series to star on "Detroit 1-8-7". Shaun returned to the show starting in the 19th season.