The characters not only avoid profanity but typically speak in a very polite and restrained manner, even when in a state of extreme emotion.
The word "idiot" used infrequently.
In one episode, "Hell", "Go to Hell", "The Devil knows", and "Damnation" are used frequently, literally, and comedically.
Most of the violence is non-graphic and played off as worse than it is to give the show a false feeling of maturity.
Early in the series, the characters speak in an incredibly polite manner. Impolite speech becomes more common as the series progresses.
"God," and "hell" respectively.