The rise and fall of Bill Cosby in American culture is a considerable tale of race and talent and decades of denial for behavior that led to his conviction of aggravated indecent assault in 2018 that was — almost as shockingly — vacated by the Pennsylvania Supreme Court last year. 

W. Kamau Bell’s “We Need to Talk About Cosby” (Showtime, 10 p.m.) is the first documentary to fully tell the tale, and takes four hours to do so. That gives time, in the early episodes to track his remarkable rise as a mainstream comic superstar, a celebrated TV star, both in “I Spy” and in a number of educational shows, mostly for kids, but also the groundbreaking 1968 documentary series “Black History – Lost Stolen or Strayed.”  

It was his eight season “The Cosby Show” from 1984 to 1992 that may have been his biggest hit — perhaps single-handedly saving NBC with a family sitcom that captured the nation depicting a successful upper middle class Black family unit that defied past stereotypes.

Bell is masterful in telling the story, often using the voices of women who later would return to be one of the 60 or so accusers over many decades that he drugged women and raped them. 

A standup comic who became an affable host of documentary series a decade ago, Bell has a pained personal connection to the stories, in that Cosby was so influential to his own comedy trajectory. So he interjects his own reactions from time to time.